Test Two Flashcards
(347 cards)
1
Q
mutations in eukaryotes
A
only in germ line cells transmiteed to progeny
2
Q
how do chloroplasts and mitochondria divide
A
they divide when the cell divides
3
Q
type one topoisomerases
A
break one of the two DNA strands and pass unbroken strand through the break and ligate the broken ends, change LK by one
4
Q
DNA pol requires
A
a free 3’OH group added to new dNTP
5
Q
the conformation change of pol occurs due to
A
the correct binding of dNTP
6
Q
hyrdolysis
A
addition of oh group
7
Q
function of pol 3
A
chromosome replication
8
Q
RPA
A
similar to SSB but for eukaryotes
9
Q
what is a point mutation
A
chang in a sinlge base pair
10
Q
what test is used to test for mutations
A
ames test,
11
Q
purpose of smc2-smc4
A
produce condensin, bind to DNA to create positive supercoils, and causes DNA to be overwound
12
Q
what are Cen proteins
A
binding site for centromere binding proteins, 5 to 10 bp sequences of thousands of tandem copies
13
Q
steps of gyrase
A
gyrase complex binds to DNA segment aka N gate, and wraps DNA around itself, positive node is in the active site, active site Tyr residues bind ATP and cleave both strands of one of the DNA segments, the other DNA strand is passed through the C gate, the DNA strands are ligated by attack of the free hydroxyl group on the phosphotyrosine residues
14
Q
mutations in prokaryotes
A
transmitted to daughter cells
15
Q
3’-5’ exonuclease is used
A
by pol to remove incorrect dNMP and does not return as dNTP
16
Q
characteristic of DNA helicase
A
ring shaped hexamers, in e.coli moves from 5 to 3 on lagging strand,
17
Q
bacterial DNA is compacted in a structure called
A
nucleoid
18
Q
what is DNA underwinding
A
molecule has fewer helical turns than expected in the B form causing it to be thermodynamically strained
19
Q
what dimers do SMC form in eukaryotes
A
heterodimers
20
Q
CDK (euk)
A
s-phase cyclin kinase
21
Q
mismatch repair system
A
repairs mismatch nucleotides from POL
22
Q
whats another way histone tails can be modified
A
recruiting enzymes that recognize particular modified aa residues
23
Q
SMC proteins are similar to
A
histones, but do not form stable structures
24
Q
do plasmids encode genes essential for their host
A
no but they are symbiotic
25
what is the zigzag model
zigzag histone pairs stack on each other and twist about a central axis, linker DNA passing through central axis
26
nonsense mutation
codes for a stop codon, premature termination
27
how does smc1-smc3 work
form a functional unit known as cohesin that links two sister chromatids after chromosomal replication and keep them together during metaphase
28
mechanisms of DNA alterations
hydrolysis, oxidative damage, alkylation, UV radiation, base misincorporation, recombinatio error
29
H1 is also known as
the linker histone
30
duplication mutation
amplification of large section of DNA, increase gene dosage
31
how many smc in eukaryotes
6
32
UvrB
unwinds DNA
33
topoisomerase 1 (euk)
removes supercoil stress
34
nick translation
5 to 3 exo nick area, pol remove RNA and ligase seals back up
35
exonuclease activity is
proofreading from 3 to 5
36
how many origin sites are in eukaryotes
many
37
how does histone and DNA bind
histone fold and phosphodiester backbone with h bonding, histone neutralizes backbone
38
what type of supercoils is introduced by bacterial topoisomerases 2
negative supercoils, actively
39
in eukaryotes are there one or numerous replication forks
numerous
40
how does the DNA look in bacteria for the chromatin
looped DNA domains that are individualized topologically
41
purpose of DNA genome
initiation, termination of replication, segregation of cell division, and protection and maintenance of the chromosome ends
42
what are the two sites called in the DNA pol active site
insertion site, postinsertion site
43
topological properties of DNA can be changed only by
the breakage and rejoining (religation) of the backbone of one or both DNA strands
44
dNA glycosylase
recognizes damaged base and cleaves base from pentose
45
Cdt1 (euk)
helicase loader
46
positive supercoiling results in
lefthanded superhelix
47
is the DNA released from the enzyme during these topological transactions
no and this so the uncontrolled relaxation of DNA does not occur
48
what is HIRA
transcriptional repressor, chromatin remodeling complex/ histone chaperone for h3.3
49
Dna2 (euk)
processes okz fragment
50
what supercoil is most common
negative
51
pol 1 (pro)
okazaki fragment processing, removes RNA and replaces it with DNA
52
Pol alpha (euk)
primase
53
the thumb domain of pol does what
curves around duplex of primed template to tighten grip of DNA
54
conservative DNA replication
1 old strand, 3 new strands
55
where does DNA bind to in H1
central globular domain at two binding sites
56
what are nucleosomes
dna wrapped around histones
57
supercoiling occurs when
torsional strain imparted to DNA by decreasing or increasing the linking number relative to that of B DNA
58
how to remove primer
nick translation from Pol 1,
59
what bases can be deaminated
cytosine, adenine, and guanine
60
negative supercoiling results in
twisting of axis of the DNA to form a right handed superhelix
61
type two topoisomerases
break both DNA strands and change LK by 2
62
SMC forms what
dimers
63
MutH
cleaves hemimethylated DNA
64
what are plasmids
smaller circular DNA molecules that are free in the cytosol
65
what are bromodomains
motifs with acetylated lys residues, usually located in a larger, multiprotein complex
66
what does H1 do with nucleosomes
stabilizing nucleosomes on the DNA and promoting higher order chromatin that further compacts DNA
67
what is supercoiling
coiling of a coil
68
is ATP needed to open beta clamp
yes
69
what are the five distinct domains of SMC proteins
amino terminal, carboxy terminal, alpha helical structure, hinge domain
70
ORC (euk)
initiator
71
primers are synthesiezed by what enzyme
primase
72
what is the primary mechanism by which underwinding contributes to genomic DNA compaction
solenoidal supercoiling
73
how is negative supercoils possible in eukaryotic DNA
tight wrapping of the DNA around a nucleosome in chromatin, which introduces a negative solenoidal supercoil without changing the number of turns in the molecule
74
pol epi (euk)
replicase
75
chromodomain recognizes
methylated lysine
76
what joins the okazaki fragmnts
ligase
77
what happens to dNTP when attaching to primer
becomes dNMP
78
what is processive synthesis
when the pol does not dissociate from DNA and just slides forward to continue
79
reading frame is
from start codon to stop
80
what is Dam methylase
methylates DNA of adenine in GATC seq, MMR can see that parent strand is methylated and new strand not and can fix any mismatch
81
how is solenoidal supercoiling formed
DNA is wrapped around the nucleosomes that make up eukaryotic chromatin
82
DnaC (pro)
helicase loader
83
frameshift mutation
one or two base pairs deleted throws off reading frame
84
what motif is present in histone
histone fold motif which has three alpha helices linked by two short loops
85
where are most mitochondrial proteins encoded
in nuclear DNA
86
nitrous acids is a mutagen to what bases
A and C
87
mitochondrial DNA codes for
mitochondrial tRNAs and rRNAs and a few mitochondrial proteins
88
what is a histone fold motif
3 alpha helices linked by two short loops
89
PCNA
DNA sliding clamp in eukaryotes
90
what is the solenoid model
spiral shape, flat sides of adjacent nucleosome disks are next to each other, linker DNA bends inside filament
91
the underwinding and relaxation of DNA are catalyzed by what enzyme
topoisomerases, by breaking one or more strand, increasing or decreasing the linking number
92
DNA ligase
seal strands using ATP, 5' of dna
93
what are the types of insertion or deletion mutations
frameshift or slippage
94
Ctf4 (euk)
scaffold
95
what does bidirectional mean in replication
initiates origin of replication, propagates in both directions from origin
96
what happens to DNA since it does not break when binding to histone
negative supercoil around histones must be accompanied by a compensatory positive supercoil in the unbound region
97
Topoisomerase 4 (pro)
removes supercoil tension
98
sigma subunit in pol 3
3 to5 exonuclease
99
what are the three main classes in chromatin remodeling complex
SWI/SNF, ISW1, NURD
100
what is linking number
number of times the second strand pierces the surface
101
what is a replication fork
point where the parental duplex separates and daughter duplexes form
102
in bacteria what is the start site for chromosomal replication
origin site
103
what are separases
enzymes used to remove cohesin tethers
104
primases
synthesize short RNA primers
105
DDK (euk)
s phase cyclin kinase
106
what are the two categories of point mutation
transition or transversion
107
what are the chromosomes like in viruses
ss stranded and double forms, RNA genomes
108
does supercoiling occur in viruses
yes but has to be double stranded DNA genome or generate ds DNA as a replication intermediate
109
function of Pol 2
translesion synthesis
110
cytosine is deaminated into what
uracil
111
what aa are rich in histones
arginine and lysine
112
what are endonucleases
nucleases that cut DNA at internal positions
113
DnaA (pro)
initiator, binds OriC
114
what is the largest protein component in chromatin
histones
115
proteins that bind to methylated Lys residues contain motifs called
chromodomain, may help promote closed state
116
mutation is
a change in DNA seq that is propagated through cellular generations
117
deletion mutations
loss of one or more base pairs
118
linear DNA are bound to what
chromatin
119
lefthanded helix causes what linking number
negative
120
Dam Methylase (pro)
methylates adenines in GATC seq
121
how is strain introduced by underwinding accomodated
separating the strands or mostly by supercoiling due to less energy needed for that
122
what are exonucleases
nucleases that shorten DNA from the ends
123
what happens to the length of telomeres overtime
reduces with age in somatic cells
124
Fenl (euk)
removes RNA primers
125
function of pol 1
okazaki fragment processing and DNA repair
126
the histone tails are important for
chemical modifications that change the chromatin
127
mechanisms of DNA repair
mismatch repair, direct repair, base excision repair, nucleotide excision repair, recombination, translesion DNA pol
128
negative supercoils is associated with
DNA underwinding, fewer turns
129
does bacterial DNA contain histones
yes, 2 subunit protein HU but dont have octamers
130
what are histone chaperones
assist the assembly of histone octamers on DNA, acidic proteins that binds to H3H4 or to H2AH2B, also function to assemble new histones on DNA during DNA replication
131
what removes acetyl groups of n tails of histones and lead to transcriptional repression
HDACs
132
SSB
binds unwound DNA
133
is epigenetics associated with direct changes in DNA sequence
no
134
Exonuclease 1
3 to 5 exonuclease
135
where does bound DNA stay in pol
in palm
136
Pol 4 and 5 used for
error prone, stress response
137
type one topoisomerases of eukaryotes are known as
type one and three
138
how many pol are present in e coli
5
139
function of kinetochore
anchors the spindle fivers as chromosomes are segregated into daughter cells during mitosis
140
what does semiconservative mean
each daughter duplex receives one complete parental strand
141
what is epigenetic inheritance
inheritance of genetic properties that are not encoded in the DNA sequence
142
function of H1
inhibit or allow transcription of DNA
143
does DNA pol a have 3 to 5 exonuclease
no
144
what is needed by topoisomaerase 2 to keep it thermodynamically favorable
ATP
145
DNA helicases
separate DNA strands using ATP hydrolysis, binds to one strand
146
H1 consists of
20 to 35 n term, central globular domain of 80 aa, 100 residues in C term
147
what chromatin remodeling complex is associated with gene activation
SWI/SNF
148
what is necessary for 30 nm filament
n term tails of core histones that provide important nucleosome-nucleosome contacts
149
what is needed for a stable artificial chromosome
centromere, telomeres, appropriate number of replication origins
150
what is TMV
tobacco mosaic virus, ss RNA, 6400 nucleotides, tight left handed helix that has a rod like helical protein coat
151
MutL
binds Muts and coordinates Repair
152
what happens with histones when transferred to daughter cells
1. old h3-h4 and new h2ah2b
2. new h3h4 and old h2ah2b
3. parental h3h4 and h2ah2b
4. entirely new octamer subunit, CAF-1 brings in new H3H4
153
replication factor C
clamp loader in eukaryotes
154
do DNA viruses become circular
yes at some point and become double stranded
155
how does DNA wrap around histone
left handed solenoidal supercoil, 6 to 7fold
156
Exonuclease 7
5 to 3
157
function of bromodomains
help stabilize the open chromatin states
158
what nucleotides are seen at OriC
A=T
159
Tus (pro)
participates in replication termination
160
indels are
insertion or deletion mutations
161
a person can inherit genes and what else
nucleosome modifications
162
in eukaryotes what other organelles contain DNA
mitochondria and cholorplasts
163
in E. Coli how many topoisomerases
4
164
is ATP used in topoisomerases type one
no
165
purpose of type one and three of eukaryote topoisomerases
relieving tension and resolving topological problems in DNA during replication and repair
166
what special enzyme is used with telomeres
telomerase used for replication
167
missense mutation
change in aa
168
purpose to type 4 bacterial topoisomerases
unlinks the catenated daughter chromosomes allowing for proper segregation during cell division, no atp and no negative
169
pol 3 used for
primary replicative enxyme
170
purpose of type 2a and B of eukaryotic topoisomerases
cant unwind DNA but can relax both positive and negative coils, play important role in condensation of chromosomes into highly structured chromatin
171
what are chromatin remodeling complexes
slide the nucleosome to a different location, eject it from DNA or replace it with a new nucleosome that contains a variant histone subunit
172
what are formed by UV induced covalent crosslinks
pyrimidine dimers
173
bacterial chromosomes are often
circular
174
what is needed for tight wrapping around histone
abundance of A=T regions that conform to the shape
175
RecJ
5 to 3 exonuclease
176
the acetylation of Lys residues in n term tails of histones is performed by what enzymes
histone acetyltransferases, HATs; they help enhance DNA accessibility and lead to transcriptional activation
177
what are some of the mechanisms used with a chromatin remodeling complex
form DNA loop around histone octamer either the nucleosome slides off promoter site or back on,
can also eject histone to generate nucleosome free region
178
what are YAC
yeast artificial chromosomes, used to confirm the function of centromeres and telomeres
179
Cdc (euk)
helicase loader
180
supercoiling is an what
intrinsic property of DNA tertiary structure
181
deamination
removal of amino group and rest of amino groups are eligible for hydrolysis attack
182
RNaseH (pro)
okazaki fragment processing, removes RNA
183
function of pol 4
translesion synthesis
184
what are okazaki fragments
short fragments produced on lagging strand
185
what is the second type of type 2 bacterial topoisomerases
type 4
186
transition point mutation
pur to pur, pyr to pyr, more freq
187
SeqA (pro)
binds hemimethylated GATC, inhibits oriC
188
Heliase 2
unwinds DNA
189
what are the types of topoisomerases in e coli
1 and 3 are like type one,
190
H3 variants in eukaryotes
susceptibility of residues of n term tail to modifications such as methylation or phosphorylation
191
replisome progression complex
large protein with pol, clamps, primer, in eukaryotes
192
what are the parts of histone
H2A, H2B, H3, H4
193
purpose of histone tails
form intermolecular contacts with adjacent nucleosome particles and order nucleosomes into a higher ordered chromatin structure
194
eukaryotes DNA organization in cell characteristic
linear chromosome, mitochondria with circular DNA, chloroplast with circular, multiple origins of replication
195
histone modifications that only affect chromatin structure by modification itself is known as
cis acting, can alter tightness of the nucleosomes
196
excinuclease
removes a lot of nucleotides from one strand during NER
197
what are chromatin remodeling complexes
2 to 18 subunits that use ATP to move nucleosomes around
198
what is negative supercoiling
underwinding
199
what are histones
highly conserved, basic proteins that assemble into octameric complexes containing two each of four different histones subunits
200
right handed helix causes what linking number
positive
201
N terminal tails of histones are targets for
reversible covalent modification
202
where is php domain located in pol 3
alpha
203
RPA (euk)
ss DNA binding protein
204
what are histone modifying enzymes
covalently modify the n terminal tails of histones, attach chemical groups to aa residues of nucleosome
205
smc5-smc6 are involved in
DNA repair
206
H1 promotes what in eukaryotes
filament formation
207
topoisomerases
cut DNA in front of helicase to prevent supercoils
208
what is gyrase composed of
GyrA and GyrB, heterotetramer
209
Mcm 2-7 (euk)
presumed helicase
210
what are closed circular DNA
DNA molecules have no breaks in either strand and is rarely relaxed
211
what ion is present in the pol active site
Mg and held in place by asp residues, so no side chain is affected during this
212
how does a histone chaperone work
CAF-1 chaperone deposits and H3-H4 tetramer onto DNA, NAP-1 chaperone assembles two H2A-H2B heterodimers with the H3H4 to form the nucleosome
213
HU (pro)
stimulates open complex at oriC
214
what is solenoidal supercoiling
tight left handed turns, negative, stabilized by proteins and is more compact
215
when does positive supercoils occur
during replication and transcription
216
Bromodomain recognize
acetylated lysine
217
what is a centromere
segment of each eukaryotic chromosome that function during cell division as an attachment point for proteinsthat link the chromosome to the mitotic spindle at metaphase
218
characteristic of pol 3
heterotrimer, 3 subunits (alpha, sigma, theta),
219
the fingers domain of pol do what
contains the dNTP binding site
220
what does the 3' end of a telomere look like
AC
221
what chromatin remodeling complex is associated with gene repression
ISWI and Mi2/NURD
222
can DNA polymerase initiate DNA chains
no, primers can only do it
223
morgan discovered
eye color is x linked with flies
224
characteristic of pol 3 holoenzyme
contains three pol 3 cores, 2 beta sliding clamps per pol 3, one clamp loader
225
how many smc in bacteria
at least one
226
pol 1 used for
replication initiation, okazaki fragment process, DNA repair
227
purpose of SMC proteins
play integral roles in DNA condensation and chromosome segregation during mitosis and DNA repair, perform tasks by lining up along DNA and binding to each other provding link between distant parts of chromosome
228
5'-3' exonuclease is used
at same time as polymerase since in the same direction, exo removes and pol replaces right after it
229
what is in a chromatin remodeling complex
ATPase subunit and use the energy from ATP hydrolysis to disrupt the contact b/w nucleosome and DNA
230
what strand is discontinous synthesis
lagging strand
231
do eukaryotes have an enzyme that introduces negative supercoils
no
232
function of pol 5
translesion synthesis
233
what did walter sutton discover
chromosomes occur in pairs, separate during cell division
234
what is alkylation
addition of alkyl group to atoms in bases or to backbone
235
gamma and x rays does what to DNA
break the strands
236
RFC (euk)
clamp loader
237
how many dna twists on histone
10.2 bp per turn
238
indels are caused by
aberrant recombination or template slippage by dna pol
239
characteristic of centromere
130 bp long very rich in A=T base pairs
240
what are the modifications that can be done to the N-term tails of histones
acetylation, methylation, phosphorylation
241
what are the three DNA replication characteristics
semi conservative, bidirectional and semi discontinous
242
Avery, Macleod, McCarty discovered
DNA vs RNA and what happens with mouse
243
what are topoisomers
two forms of a circular DNA that differ only in topological properties such as linking number
244
SSb (pro)
stabilizes and protects ss DNA
245
dispersive DNA replication
all four strands have new and old
246
pol sigma (euk)
replicase
247
MUTs
recognizes single base mismatches
248
can unwinding the DNA cause strains
yes and result in supercoils
249
prokaryotes dna organization in cell characteristic
circular chromosome, plasmids, single origin of replication
250
what does the 5' end of a telomere look like
TG
251
insertion mutations
one or more base pairs are added
252
how many H1 subunits
one
253
what is compaction in chromosomes
coiling and structural organization of the chromosome due to enzymes
254
what are the two types of excision repair
base excision repair and nucleotide excision repair
255
griffith discovered
different strains of virus with mice
256
what is a point mutation
change in nitrogenous base
257
purpose of GyrB
interacts with DNA and ATP and catalyzes ATP binding and hydrolysis
258
is the lagging strand continuous or semidiscontinuous
semi
259
how is underwound state maintained
DNA is a closed circle, or if linear, bound and stabilized by proteins so the strains are not free to rotate
260
Ligase (pro)
okazaki fragment processig, joins segments
261
where is DNA stored in mitochondria
kinetoplasts
262
what facilitates DNA structural changes
underwinding
263
what is the origin of replication
point where DNA synthesis starts due to a specific sequence
264
cholorplast DNA exists in what form
circular duplexes
265
DNA pol requires
template strand, primer strand with a free 3' oh group,
266
what is the C gate
exit way for DNA formed by GyrA
267
what is a replisome
pol 3 holoenzyme, DnaB helicase, primase
268
function of plasmids
replicate to create daughter plasmids that are transferred to new cells during cell division
269
common types of mutation
point, insertion and deletion, large scale mutations
270
primers at replication fork are DNA or RNA
RNA
271
what is positive supercoiling
overwound
272
where is most of the mass in a histone
in the center but N termini are present and they are flexible and disordered
273
RNA pol (pro)
stimulates open complex at oriC
274
what is the first level of DNA packaging in eukaryotes
DNA plus histone proteins
275
UvrA
recognizes lesion
276
what does it mean that nucleosomes are intrinsically dynamic
intercations that hold nucleosomes arrays together are weak, allowing for H bonds to break and reform of Histones and DNA very easily
277
what are topoisomers
enzymes that catalyze DNA undwinding
278
H2A variants in eukaryotes
differ in c term tail which recruite various proteins to nucleosome
279
what are the two systems of regulation of eukaryotic chromosomes
chromatin remodeling complex and histone modifying enzymes
280
what is the N gate
part of GyrB that forms entry way for DNA
281
bacterial topoisomarse 2 are known as
gyrase
282
importance of DNA replication
required for cell division, transfer info across generations, regulated process, complex cellular machinery, high fidelity, principles similar in all life forms, mechanisms and complexity varies
283
what nucleotide is usually methylated
C if followed by G
284
DNA ligase 1 (euk)
seals okz fragments
285
transversion point mutation
purine to pyrimidine
286
pol 3 holoenzyme (pro)
chromosomal replicase
287
what is cross linking
a chemical with two reactive groups is used to react with a protein complex
288
bacteria contain what
plasmids
289
when is replication not bidirectional
e coli plasmids unidirectional, viruses with linear chromosomes with replicate from ends
290
silent mutation
no change in aa
291
what is cytotoxic
mutagen that causes cell to die
292
what is smc1 -smc3 and smc2-smc4 used during
mitosis
293
what is a replicon
total length of DNA replicated
294
is the leading strand, semidiscontinuous or continuous
continuous
295
what is DNA nucleases
degrade DNA
296
what is pol 3 holoenzyme
contains pol 3, and replicates both leading and lagging strand
297
what are HACs
human artificial chromosomes, provide new ways to treat diseases
298
what is chromatin
materials of chromosomes both protein and DNA
299
who determined the composition of DNA
miescher
300
most eukaryotic chromosomes are often
linear
301
UvrD
helicase
302
what was the disperative method for DNA replication
the duplex would be replicated in a random patchwork, 3/4 new and 1/4 old
303
who came up with semiconservative
watson and crick
304
DNA underwinding helps maintain
the required strand separation in regions where palindromic sequences allow cruciform formation
305
what is genotoxic
chemical changes in genomic DNA
306
is supercoild DNA strained
yes
307
purpose of GyrA
binds to another part of DNA and promotes DNA wrapping
308
what kind of supercoiling do you see in plasmids
plectonemic supercoiling, right handed, negative, more stable in solution
309
what are the type two topoisomerases of eukaryotes
type 2a and 2b
310
what is different in prokaryotic DNA organization
higher metabolic rate, higher coding fraction in genome, faster replication times
311
what are telomeres
sequences at the ends of eukaryotic chromosomes that add stability by protecting the ends from nucleases and providing unique mechanisms for replication of linear DNA molecules
312
boveri discovered
chromosome number
313
single stranded dna binding protein (SSB)
protects DNA from endonucleases, stimulates DNA pol activity by melting hairpin structures
314
inversion mutation
inversion of large section of DNA in chromosome
315
what is the initiator protein
binds specific sites at origin, start strand separation
316
what does semi discontinous mean in dna replication
one strand ( 5to3) synthesized continously, second strand senthesized in opposite direction, requires periodic reinitiation
317
what are large scale mutations
single chromosome mutations, deletion, inversions and duplication
318
Hda (pro)
induces DnaA to hydrolyze ATP
319
UvrC
excinuclease
320
what is the area called where the dNTP's are added to the primer
primer terminus
321
PCNA (euk)
sliding clamp
322
what linking number is never encountered
negative
323
what dimers do SMC form in prokaryotes
homodimers
324
positive supercoils is associated with
DNA overwinding, more turns
325
semiconservative DNA replication
2 old and new, 2 new
326
what is an abasic site
hydrolytic attack on backbone and base causing base to leave backbone
327
underwinding of the right handed DNA also facilitates
the formation of short stretches of left handed z DNA regions
328
topoisomerse 2 (euk)
removes supercoil stress
329
translocation mutation
non homologous chromosomes exchange large regions of DNA
330
Gyrase (pro)
type 2 topoisomerase
331
what is relaxed DNA
when there is no net coiling of DNA axis upon itself
332
accomplishments of underwinding DNA
promote its compaction of coiling, facilitates strand separation and enzymatic access to the encoded info for replication and transcription
333
H1 alters what of DNA
entry and exit of DNA
334
where does DNA attach in prokaryotes
to inner surface of cell membrane
335
what is distributive synthesis
when pol dissociates from DNA and rebind the primer strand terminus to the postinsertion site
336
how does the SMC protein work
when hinge domain bends, the alpha helical regions form a coiled coil motif, and the N and C domains come together to to form a head structure at one end with an ATp binding site, 2 head domains and 2 atp binding sites
337
histone modifications that act through molecules other than chromatin itself is known as
trans acting, attract proteins such as transcription factors
338
Exonuclease x
3 to 5
339
when DNA not bound to histone what happens
H3 and H4 form heterotetramer and H2A and H2B form heterodimer
340
DnaB (pro)
helicase
341
primase (pro)
synthesizes lagging strand RNA primers
342
are histone modifications inheritable
yes
343
what happens with phosphorylation of histone tails
occurs on tails on H3 and H4, phosphorylates Ser, Thr and tyr which incorporates a negative charge to tail
344
size of mitochondrial DNA to nuclear dna
much smaller, circular duplex
345
RnaseH
remove RNA but cant remove last rNMP attached to DNA
346
alpha subunit in pol 3
dna poly activity
347
what does helicases require for translocation
dNTP's
