Symes DNA Replication Flashcards

1
Q

OriC

A

Replication initiation region in prokaryotes
- 3 AT-rich sequences
- 4 9bp sites (DNAa binding domain)

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2
Q

DNAa

A

Initiatior proteins which binds causing the DNA to bend
- splits DNA apart
- binding mediated by positive histone-like proteins
- prokaryotic

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3
Q

DnaB/C

A

Helicase which displaces DNAa
- prokaryotic

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4
Q

SSBs

A

Stabilise ssDNA
- prokaryotic

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5
Q

DnaG

A

Part of the primosome, makes primers
- prokaryotic

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6
Q

Function of DNA Pol 1

A

Performs primer excision and DNA repair
- fills in gap left behind by primer
- prokaryotic

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7
Q

What does the 3’ exonuclease of DNA Pol 1 do?

A

Proofreading, removes wrong base
- prokaryotic

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8
Q

Function of 5’ exonuclease of DNA Pol 1

A

Removes primers (nick translation)
- prokaryotic

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9
Q

Nick Translation

A

5’ exonuclease removes primer one base at a time until it reaches DNA
- DNA Pol 1 fills in the gap
- DNA ligase then seals the gap

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10
Q

DNA Pol III

A

Performs the bulk of replication in prokaryotes
- high processivity and high rate
- prokaryotic

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11
Q

Subunits in core enzyme of DNA Pol III

A

Dimer of alpha, epsilon (3’ exo), theta
- prokaryotic

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12
Q

beta sliding clamp

A

Part of DNA Pol III
- improves processivity
- negative amino acids on the interior
- prokaryotic

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13
Q

Gamma complex

A

beta clamp loader
- chi subunit helps DNA Pol III transition form making RNA primer to making DNA

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14
Q

Replisome

A

Creation of a loop at the replication fork so DNA Pol III can go in the same direction on both strands

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15
Q

What perfroms proofreading in prokaryotes

A

Epsilon subunit of DNA Pol III removes the mismatched base with its 3’ to 5’ exonuclease

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16
Q

How does termination in prokaryotes occur?

A

ter and TUS proteins
- topoisomerase 2 then separates and relegates the interlinking strands

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17
Q

4 similarities between prokaryotic and eukaryotic replication

A

1) semi-conservative
2) Bi-directional
3) requires RNA primers
4) Leading strand and Okazaki fragments

18
Q

Prokaryotic initiation mechanism

A

Initiation begins at a single initiation site with additional rounds started before completion of the first round

19
Q

Prokaryotic Priming mechanism

A

Provides an unreacted 3’ OH to allow DNA Pol to bind
- RNA primer: 5-10 nts, made 5’ to 3’

20
Q

DNA Polymerase Gamma

A

Found in the mitochondria

Eukaryotic

21
Q

DNA Polymerase Beta

A

Responsible for DNA repair

Eukaryotic

22
Q

DNA Polymerase alpha

A

Contains the primase, makes RNA Primer
- no proofreading

Eukaryotic

23
Q

DNA Polymerase delta

What does it do?

A

Responsible for lagging strand replication
- combines with epsilon to fill in gap left behind by RNA primer

Eukaryotic

24
Q

DNA Polymerase Epsilon

A

Responsible for leading strand replication
- combines with delta to fill in gap left behind by RNA primer

Eukaryotic

25
Q

What happens to nucleosomes in eukaryotic replication?

A

Dissociate ahead of the fork, then resynthesize after it

Eukaryotic

26
Q

ORC

A

Binds next to AT-rich regions to bend DNA

Eukaryotic

27
Q

MCMs

A

Helicase
- mini chromosome maintenance proteins

Eukaryotic

28
Q

RPA

A

SSBs
- Replication Protein A

Eukaryotic

29
Q

PCNA

A

Beta-clamp

Eukaryotic

30
Q

RFC

A

Clamp loader
- Replication Factor C

Eukaryotic

31
Q

RNase H/Fen1

A

Removal of RNA primers

Eukaryotic

32
Q

Licensing

A

Part of replication
- assembly of pre-replication complex on ARS
- pre-RC contains ORC, inactive MCMs, others

Eukaryotic

33
Q

ARS

A

Origin of replication

Eukaryotic

34
Q

Firing

A

Part of replication
- Helicase is activated, activating the RC

Eukaryotic

35
Q

hTERT

A

Protein component of reverse transcriptase

36
Q

hTR

A

Template for hTERT
- RNA component of reverse transcriptase

37
Q

t-loop

A

Leftover overhang which comes in and displaces dsDNA to make a D-loop-t-loop

38
Q

Dyskeratosis Congenita

A

Mutations in hTERT/hTR which cause premature mortality
- example of anticipation

39
Q

Function of chi subunit of gamma subunit

A

Interacts with SSBs to transition DNA over to DNA Pol III for replication

40
Q

Which polymerase does PCNA increase the processivity of?

A

Delta