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Chapter 11: DNA Replication - Coggle Diagram
Chapter 11: DNA Replication
Bacteria
OriC: AT-Rich regions, GATC Methylation sites, DnaA boxes. Binding of DnaA proteins causes the AT-rich region to open up, allowing DNA helicase to bind and separate the two strands, moving in the 5' to 3' direction
Dam methylation of GATC sites necessary for replication to begin.
DNA Pol III synthesizes the daughter strand on both the leading and lagging strand.
Alpha = synthesizes; epsilon proofreads; Beta = clamp.
DNA Pol I exices the RNA primers and fills in the gaps with DNA. Gaps between Okazaki fragments is ligated with DNA Ligase.
Okazaki fragment = 1000-2000 BP's nucleotides.
DNA Pol I has 5' to 3' exonuclease activity (digests in the 5' to 3' direction).
Primosome: DNA Helicase and DNA Primase
Catenanes separated by Topoisomerase II
Proofreading occurs by the removal of nucleotides in the 3′ to 5′ direction at the 3′ exonuclease site.
DNA Polymerases III and I
Induced-Fit Phenomenon: Decreases the error rate to a
range of 1 in 100,000 to 1 million
Eukaryotes
ARS Elements: 50 BP in length
Prereplication complex (preRC), takes place at G1 phase. Involves ORC binding to the ARS, then recruits cdt1 and cdc6.
MCM Helicase moves in the 3' to 5' direction
GREEK DNA Polymerases Alpha, Epsilon, Delta, Gamma
Epsilon = lEading strand
Alpha = initiates in conjugation w/primase
Delta = lagging stranD
Gamma = mitchondrial
Flap endonuclease removes RNA primers, 5 to 3' direction
SINES = 10% human genome; LINES = 17% human genome
Telomeres
3' overhang
Telomerase - attaches to 3' overhang; polymerizes, then translocates.
Transposons: LTR Retrotransposons, encode integrase and reverse transcriptase.
Non-LTR example: Alu, over a million copies in human genome
Non-LTR retrotransposons move via target-site primed reverse transcription