DNA replication--general principles

Question 1

What is the function of Zinc finger proteins?

Answer 1

Contain zinc ions, which are important for protein folding

Bind to major groove of DNA

Question 2

Where do specific protein interactions mostly occur?

Answer 2

-specific interactions allow binding to a
specific sequence – interactions with the
edges of the bases of DNA – mostly in the
major groove

Question 3

Where do nonspecific protein interactions often occur?

Answer 3

phosphate backbone

Question 4

List 4 types of protein structure that often bind DNA. Where do they usually bind?

Answer 4

• helix turn helix
• zinc finger
• leucine zipper
• helix loop helix

Major groove

Question 5

Why does DNA polymerase need a primer?

Answer 5

DNA polymerase only adds a nucleotide to the 3’ end of an existing molecule,
therefore you also need a PRIMER that DNA polymerase can extend

Question 6

In what direction is DNA synthesized?

Answer 6

5’ -> 3’

Question 7

What type of replication occurs on the lagging strand?

Answer 7

Discontinuous, with Okazaki fragments

Question 8

Which strand is the lagging strand?

Answer 8

3’ -> 5’ strand of the replication fork

Question 9

Which exonuclease has proofreading activity? What molecule is it part of?

Answer 9

3’ to 5’ exonuclease activity to remove the incorrect nucleotide

Part of DNA polymerase

Question 10

What enzyme relieves tension in supercoiled DNA?

Answer 10

topoisomerase

Question 11

What is the primer for DNA replication made of?

Answer 11

RNA

Question 12

How does DNA Pol structure promote fidelity?

Answer 12

Pocket in the polymerase accomodates a purine-pyrimidine pair well–other pairs, not so much