[2S] UNIT 5 Characterization of Nucleic Acid Flashcards
(170 cards)
Degrade DNA molecules by breaking the phosphodiester bonds that link one nucleotide to the next in a DNA strand.
Nucleases
NUCLEASES SPECIFICITY
Specific for DNA
DNAse
NUCLEASES SPECIFICITY
- Targets RNA
- Degrades all RNA
RNAse
NUCLEASES SPECIFICITY
- Able to cleave DNA and RNA hybrid
- Subtype of RNase
RNAse H
NUCLEASES SPECIFICITY
Degrades RNA bound covalently to DNA
RNAse H
When a nuclease hydrolyzes an ester bond in a phosphodiester linkage, it will have a specificity for either of the two ester bonds. This generates what nucleotides?
5’ nucleotides or 3’ nucleotides.
For single strand molecules (RNA), ______ can rapidly degrade RNA molecules into ribonucleotide subunits.
ribonuclease
TWO TYPES OF NUCLEASE
Hydrolyze internal bonds within a polynucleotide chain
Endonuclease
TWO TYPES OF NUCLEASE
● Cut the length of the DNA sequence
● Break internal phosphodiester bonds
Endonuclease
TWO TYPES OF NUCLEASE
Cut at any point depending on its target site
○ Usually in the middle portion of the fragment
○ Between the 5’ and 3’ terminus
Endonuclease
TWO TYPES OF NUCLEASE
Produce several segments of our polynucleotide
Endonuclease
TWO TYPES OF NUCLEASE
Target and remove the terminal nucleotide
Exonuclease
TWO TYPES OF NUCLEASE
Removes nucleotides one at a time from the end of a DNA molecule
Exonuclease
TWO TYPES OF NUCLEASE
Cuts the terminal nucleotide whether it is on the 5’ or 3’ (only at the end of the fragment)
Exonuclease
MECHANISM OF NUCLEASE HYDROLYSIS
Removes nucleotides from both strands of a double-stranded molecule
Bal31
MECHANISM OF NUCLEASE HYDROLYSIS
Progressive shortening of the dsDNA from both ends after treatment
Bal31
MECHANISM OF NUCLEASE HYDROLYSIS
● Removes nucleotides from the 3’ terminus
● Can only cut through double strands
Exonuclease III
MECHANISM OF NUCLEASE HYDROLYSIS
Cleaves only single-stranded DNA, including single-stranded nicks in mainly double-stranded molecules
S1 Nuclease
MECHANISM OF NUCLEASE HYDROLYSIS
Can only cut single strands nucleotides
○ Create a nick in our double stranded nucleotide
○ Cannot entirely cut the sequence (double
stranded)
S1 Nuclease
MECHANISM OF NUCLEASE HYDROLYSIS
Refers to a specific type of discontinuity
Nick
MECHANISM OF NUCLEASE HYDROLYSIS
You need another digestion for that exposed single strand to fully cut the segment
○ However, if your DNA is single stranded, it
can entirely create fragments
S1 Nuclease
MECHANISM OF NUCLEASE HYDROLYSIS
Cleaves both single and double-stranded DNA
DNAse I
MECHANISM OF NUCLEASE HYDROLYSIS
Depending on which part it attaches to or targets
○ Can cleave segments or several segments
DNAse I
MECHANISM OF NUCLEASE HYDROLYSIS
Produce mononucleotide
DNAse I