DNA Synthesis and Replication Flashcards
which eukaryotic dna polymerases are involved in dna replication
polymerase alpha, delta and epsilon
eukaryotic replicons are how many kb in length
40-100 kb in length
individual replicons are activated at characteristic times during
s phase
what is a licensing factor
a factor located in the nucleus and necessary for replication that is inactivated or destroyed after one round of replication
list three licensing factors
MCM proteins, Cdc6 and Cdt1
what is ORC
a protein complex that is associated with origins throughout the cell cycle
Cdc6 protein is an unstable protein that is synthesised only in
G1
Cdc6 binds to ORC and allows what proteins to bind
MCM proteins
which protein facilitates MCM loading onto the origins
Cdt1
Once replication starts which proteins leave ORC
Cdt1 and Cdc6
negative regulation of replication involves the synthesis of ___ by G2 nuclei
geminin
geminin sequesters which protein preventing MCM protein assembly
Cdt1
when is geminin degraded?
on completion of mitosis so that DNA can recommence replication at the next S phase
dna is synthesised by adding nucleotides to the
3’ OH end
what type of reaction do dna polymerases allow
nucleophilic attack by the ribose 3’OH group on alpha phosphate of the incoming nucleotide triphosphate and release of pyrophosphate
