dna Rep Bac

Question 1

DNA replication terminates at what degree from origin.

Answer 1

180

Question 2

Replication bubble forms having what on each end

Answer 2

Replication fork

Question 3

DNA Polymerase requires what 4 things

Answer 3

1) Primer DNA with free 3’ OH
2) Template DNA to specify the sequence of the new strand
3) Substrates - dNTPs
4) Mg2+

Question 4

DNA replication is what

Answer 4

Bi directional

Question 5

DNA polymerase 1 does what

Answer 5

Clean up - nicks
5’ to 3’ exonuclease
Abundant, not ideal for replication
Low processivity

Question 6

DNA pol 3 is for what

Answer 6

Replication

Question 7

DNA pol 2/4/5 is for

Answer 7

Repair

Question 8

All DNA polymerase have what

Answer 8

Exonuclease in 3’ to 5’ direction

Question 9

What is the klenow fragment

Answer 9

Large protein fragment
Retains 5’ to 3’ polymerase activity
Retains 3’ to 5’ polymerase activity
Loses 5’ to 3’ exonuclease activity

Question 10

When is the klenow fragment produced

Answer 10

When DNA pol 1 undergoes protease treatment

Question 11

Why does the klenow fragment retain polymerase activity

Answer 11

For removal of primer nucleotides and proofreading

Question 12

A nick is what

Answer 12

A broken phosphodiester bond leaving 3’hydroxyl and free 5’ phosphate

Question 13

Where is the nick usually found

Answer 13

At the beginning of DNA synthesis

Question 14

What DNA polymerase repairs the nick but also does what

Answer 14

Pol 1 repairs the nick but leaves a nick when it dissociates off

Question 15

What are the two core domains in Pol3 composed of

Answer 15

Alpha, epsilon and a theta

Question 16

The two core domains in DNA pol 3 is linked by what complex

Answer 16

Clamp loading 5 subunit y complex

Question 17

The clamp loading 5 subunit y complex is made of what subunits
2 τ units (dnaX)
1 γ unit (also dnaX)
1 δ subunit (holA), and 1 δ’ subunit (holB)

Answer 17

Hugh

Question 18

The core domains each interact with what

Answer 18

A dimer of β units (dnaN)

Question 19

2 β units (dnaN) act as what in DNA pol 3

Answer 19

Act as sliding DNA clamps

They keep the polymerase bound to the DNA - increase processivity

Question 20

the α subunit is encoded by what gene and does what

Answer 20

encoded by the dnaE gene) has the polymerase activity

Question 21

the ε subunit is encoded by what gene and does what

Answer 21

(dnaQ) has 3’→5’ exonuclease activity

Question 22

the θ subunit is encoded by what gene and does what

Answer 22

holE and stimulates the ε subunit’s proofreading

Question 23

2 τ units is encoded by what gene and does what

Answer 23

(dnaX) which acts to dimerize two of the core enzymes (α, ε, and θ subunits).

Question 24

1 γ unit is encoded by what gene and does what

Answer 24

dnaX
Acts as a clamp loader for the lagging strand Okazaki fragments, helping the two β subunits to form a unit and bind to DNA.

Question 25

δ does what in pol 3

Answer 25

The δ is involved in copying of the lagging strand.

Question 26

How does the pol3 complex Interact with the DNAB helicase

Answer 26

Through the t subunit

Question 27

DNA replication in ecoli requires

Answer 27

Replisome

Question 28

Replisome is made of what 5 things

Answer 28

Helicase (uses atp)
Topoisomerases (DNA gyrase, supercoiling)
DNA single strand binding
Primase - for RNA Primer
DNA Ligase - seals nicks