DNA replication #1

Question 1

Indicator protein

Answer 1

opens up double helix and recruits helicases

Question 2

ssDNA binding proteins

Answer 2

protect ssDNA
Bacteria = SSB
Eukaryotic = RPA

Question 3

Helicase polarity

Answer 3

the direction moved on the strand that is bound

Question 4

DNA gyrase (II)

Answer 4

introduces negative supercoils

Question 5

What three things does DNA synthesis require?

Answer 5

~ dNTPs
~ primer:template junction
~ DNA polymerase

Question 6

dNTP means…

Answer 6

Deoxynucleotide triphosphate

Question 7

Processive synthesis

Answer 7

replicative polymerase stay attached for many 1000s of nucleotides

Question 8

Distributive synthesis

Answer 8

some DNA pols only add a few nucleotides before falling off

Question 9

PCNA

Answer 9

proliferating cell nuclear antigen
~ common in proliferating cells
~ eukaryotic
~ ring structure made up of 3 polypeptide each with two domains

Question 10

Origin

Answer 10

the ability to bind initiator proteins

Question 11

ORC

Answer 11

Origin recognition complex
~ binds to eukaryotic origins
~ indicator protein

Question 12

Primer

Answer 12

a short piece of RNA or DNA+RNA and is synthesised by DNA primase (a type of RNA polymerase)

Question 13

Which direction does bacterial DNA helicase work?

Answer 13

5’ –> 3’ on lagging strand

Question 14

Which direction does eukaryotic DNA helicase work?

Answer 14

3’ –> 5’ leading strand

Question 15

What is the core of eukaryotic DNA helicase?

Answer 15

Mini chromosome maintains (MCM)

Question 16

What is the bacterial DNA helicase?

Answer 16

DnaB

~ lodged onto DNA by DnaC

Question 17

Which DNA pols for bacetria/eukaryotes use?

Answer 17

Bacteria = DNA pol III
Eukaryotes = DNA pol II, delta and epsilon

Question 18

Topoisomerase

Answer 18

releases supercoiled DNA by breaking it, allowing the supercoils to relax and rejoining it