De Girolamo 2 Flashcards
What base pair sequence is the starting point?
OriC
What’s bidirectional replication?
Where replication proceeds outwards from 2 replication forks
What happens in imitation and unwinding?
Involves in assembly of replication fork (bubble) at an origin
Initiator protein is dnaA
DNA helicase and primase
Helicase breaks the bonds
What does DNA helicase do?
Breaking the H bonds that join the complementary bases
SSB proteins?
Stop the unwound DNA from rejoining
DNA gyrase
Reduces torsional strain
What happens in primer synthesis?
Marks beginning of synthesis of new DNA molecule
What are primers?
Short stretches of nucleotides 10-12 bases in length
How many amino acids are there in polymerase 1?
928
3 properties in DNA polymerase
1- incoming base is selected within DNA polymerase active site by Watson crick at-gc pairing with template strand
2-chain growth is in the 5’-3’ direction
3-cannot initiate DNA synthesis
What are Polymerases active sites?
5–>3 polymerase activity (synthesis)
5—>3 exonuclease activity (primer removal)
3–>5 exonuclease activity (proofreading)
What’s a Klenow fragment
Where pol 1 is cleaved in the 5–>3 direction
DNA polymerase is not the replicative polymerase, why?
- enzyme is too slow
- enzyme is too abundant
- dna pol cannot initiate DNA synthesis
What is the main replicase?
DNA pol 3
What’s the holo enzyme
Multi subunit of pol 3
