Oct 7 Flashcards
What key proteins modulate the cell cycle?
Cyclin and cyclin dependent kinases
What direction is the template strand read and the the new one synthesised?
It is read 3 to 5 prime, but replicated 5’-3’
What 2 interactions must happen to add another dNTP to the DNA strand?
The 3’ OH group must attack the alpha PO4 of the new dNTP, and the dNTP must H bond with the base on the parent strand
What does high enzyme processivity mean?
It means can catalyze many reactions without release substrate.
How many active sites does DNA poly have for the dNTPs?
Only 1 active site
What must DNA polymerase be able to distinguish?
The correct dNTP, if it is dNTP or NTP with the OH on 2’
What is ddNTP?
It does not have either OH, so will terminate DNA synthesis
How does DNA polymerase distinguish between NTP and dNTP?
It has a group of discriminator amino acids, if OH is present it misaligns the dNTP so the PO4 is not in the correct position to be attacked by 3’ OH
What are the palm, finger, and thumb roles of DNA polymerase?
Palm has active site with metals, catalyzes OH attack to PO4. Fingers hold dNTP in place, thumb keeps primer and dNTP in place
Exo vs endo nucleases?
Exo cut from edge of strand, endo picks a spot in mid of strand to cut and start taking of nucleotides
What exonuclease activity does DNA polymerase have?
It has 3 to 5’ exonuclease activity to proofread newly synthesized DNA
What unwinds DNA?
Helicase
What is DNA polymerase a and the other name for it?
It is primase, will add RNA to make lagging strand
What removes the RNA primers so DNA polymerase can replace it with DNA?
RNase H
What will repair nick in DNA on lagging strand?
DNA primase
