免疫学信息网 . rf-c is a five-subunit complex all subunits are related in sequence and have...
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免疫学信息网 http://www.immuneweb.com
免疫学信息网 http://www.immuneweb.com
免疫学信息网 http://www.immuneweb.com
免疫学信息网 http://www.immuneweb.com
免疫学信息网 http://www.immuneweb.com
RF-C is a five-subunit complexAll subunits are related in sequence and have ATP binding motifsATP hydrolysis by RF-C is associated with the loading of PCNARF-C is the functional homolog of the clamp-loader complex
免疫学信息网 http://www.immuneweb.com
免疫学信息网 http://www.immuneweb.com
Polymerase switching occurs even on lagging strands; pol does most of DNA synthesis
免疫学信息网 http://www.immuneweb.com
免疫学信息网 http://www.immuneweb.com
How do you think the PCNA is removed after ligation?
免疫学信息网 http://www.immuneweb.com
免疫学信息网 http://www.immuneweb.com
PCNA interacts with RF-C, pol , Fen1, DNA ligase,CAF1 and MCMT
Several of these have a common motifused in the interaction: Q-X-X-L/I/M-X-X-F-F/Y
p21/CIP1/WAF1, a protein induced by the tumor suppressor p53 uses the same motifto interact with PCNA
What effect is p21 expected to have on DNA replication/repair?
免疫学信息网 http://www.immuneweb.com
FEN1 interacts with PCNA
免疫学信息网 http://www.immuneweb.com
DNA Helicase
* Helicase binds ss DNA
* Hydrolyzes ATP to move alongssDNA and peel of substrate DNA
* Can move 5‘ to 3’ or 3‘to 5’ or in both directions on ssDNAand is classified as such
* Dimers or hexamers
P P
5‘ 3‘
3‘ 5‘ 5‘3‘
Substra
te
Boiled su
bstra
te
+he
licas
e
+helic
ase+
ATP
15mer 30mer
15mer30mer
免疫学信息网 http://www.immuneweb.com
Conserved helicase motifs:
Includes the following for ATPbinding and hydrolysisI = Walker A motif GxGxGKTII = Walker B motif DEad
Binds ATP
Tight conformation
Hydrolyzes ATP
Relaxed conformation
Helicases are ATP driven molecular motors