Question

7. What protein/protein complex in E. coliserves a similar function as MCM2-7?

8. What protein/protein complex in a human cell nucleus serves a similar function as the ?-clamp in E. coli?

11. What does telomerase and the ORF2 gene product of the L1 retrotransposon have in common?

Answer 1

7. MCM proteins are ring shaped replicative helicase similiar to DnaB helicase in E.coli which unwinds the DNA at the origin of replication.

8. Proliferating cell nuclear antigen (PCNA) in human cell serves as a similiar function as the  ? -clamp in E.coli. PCNA is the sliding clamp in eukaryotes assembeled from a specific subunit of DNA polymerase delta. Both the clamp( ? clamp and PCNA) prevents the polymerase from falling off DNA.

11. Reverse transcriptase .

Telomerase is a ribonucleoprotein enzyme,found at end of telomere and helps in the synthesis of repeating T and G rich sequence at the telomeric end using the property of reverse transcriptase.

The ORF 2 of L1 encodes a protein that has an endonuclease and reverse transcriptase activity.

So the common in both is a reverse transcriptase .