Initiation
DNA A- opens strand at ori, binds ori c
unwinds DNA beginning at AT rich region
SSB binds
Recruits DNA B and DNA C complex
DNA C loads DNA B onto single strand
DNA B unwinds DNA & recruits G primase
Replication in Prokaryote requires
Helicase, DNA template, RNA Primers, DNA Pol lll, DNA Pol l, DNA Ligase
DNA Pol lll made up of
replisome, Beta 2 sliding clamp, alpha, epsilon, theta
2 Mg 2+ are necessary for ______ function
DNA Polymerase
Euk vs Pro origin of replication
euk= many origins of replication( origin of replication complex [ORC])
prok= single origin of rep
ORC similar to _____
DNA A, unwind DNA recruit other factors
Linking number (Lk)
number of times DNA winds in right handed helical direction when
constrained to a single plane
Topoisomerases
1&2
DNA molecules that differ in linking number, must be cut
top l: changes linking number by 1
top 2: changes linking number by 2
Writhe (Wr)
number of times double stranded helix crosses over itself
Twist (Tw)
number of times DNA twists around itself
Equation relating Tw, Wr, and Lk
Lk=Wr+Tw
DNA Pol l
Prok:
erases primer & fills in gaps on lagging strand
DNA Pol lll
Prok:
Primary enzyme of DNA synthesis
DNA Pol alpha
-primase subunit
-DNA Pol unit
EUK:
Initiator polymerase
-synth RNA primer
-add stretch of ~20 nucleotides to primer
DNA Pol E
EUK:
Primary enzyme of DNA synth leading strand
DNA POL Delta
EUK:Primary enzyme of DNA synth lagging strand