Lecture 4 Dr. Williams

Question 1

Importance of TBP?

Answer 1

Allows for precision binding of the transcription machinary

Question 2

How does the pre-initiation complex form?

Answer 2

Binding of TFIID, followed by assembly of multi-protein complex that eventually includes polymerase

Question 3

How many subunits does RNA Pol II have?

Answer 3

12 subunits

Question 4

Protein binding can alter?

Answer 4

Transcription rates: positive or negative

Question 5

Lac Operon low lactose:

Answer 5

Lac repressor binds tightly t o lac operator and block RNA pol access to promotor

Question 6

Lac Operon elevated lactose:

Answer 6

low levels of beta-galactosidase activity results in formation of allolactase

Question 7

Define: Dyad Symmetry

Answer 7

Palindromic sequence that may indicate a protein complex with two identical subunits

Question 8

Define: DNA Binding Domains

Answer 8

contain discrete domains that specifically interact with unique DNA elements. Organized into families based on conserved BDBs.

Question 9

Most common DBD in bacteria?

Answer 9

Helix-Turn-Helix motif

Question 10

Helix-Turn-Helix

Answer 10

fits into the major groove of DNA, and recognizes something

Question 11

Name 3 DBDs utilized in eukaryotic DNA binding proteins:

Answer 11

Zinc Finger
Basic region-leucine zipper
Basic region-helix-loop-helix

Question 12

Zinc Finger

Answer 12

zinc atom interacts with major groove

Question 13

Describe function of: CRP-cAMP complex

Answer 13

Proteins that make direct contact with RNA polymerase, and makes it more likely to unwind DNA and initiate transcription

Question 14

Define: Chromatin

Answer 14

The state in which DNA is tightly bound by histones and is unavailable for transcription

Question 15

How to remodel chromatin?

Answer 15

modification DNA by methylation
modification of histones (Acetylation, ubiquitylation, SUMOylation, methylation)
Rearranging nucleosomes

Question 16

Where does DNA methylation occur?

Answer 16

C5 of Cytosine in a CpG dinucleotide

Question 17

What is SWI-SNF remodeling comples?

Answer 17

A multisubunit that destabilizes the chromatin structure and gives transcription machinery access to the promotor. Uses ATP hydrolysis to alter nucleosome positioning

Question 18

Fragile X Syndrome

Answer 18

X-linked recessive neurological disorder caused by mutations in the FMR1 gene that codes the FMRP protein, a RNA binding protein that plays a role in translation regulation. This mutational event is an expansion of the CGG triplet expansion diseases.

Question 19

Define: Genomic Imprinting

Answer 19

Somatic cells that have methylated alleles from either parent

Question 20

Angelman Syndrome

Answer 20

Maternal SNRNPN and UB3A is missing, paternal UB3A is imprinted “off” leading to severe intellectual disabilities, and developmental delay. Happy demeanor, and microcephaly, possibly with seizures

Question 21

Prader-Willi Syndrome

Answer 21

Paternal SNRNPN and UB3A are missing, and maternal SNRNPN is imprinted “off”, resulting in initial failure to thrive, later increased interest in food, and mild intellectual disabilities, and possibly behavior issues

Question 22

Define: SNRNPN

Answer 22

Small nuclear ribonucleoprotein