Quiz 8

During SV40 DNA replication, the supercoiling of the dsDNA is inevitable. Which of the following statement correctly illustrates the different mechanisms of supercoiling removal during replication and after replication (terminal resolution)? A. During replication single strand nicks are responsible for supercoil relaxation whereas double stranded nicks are responsible for supercoil relocation (terminal resolution) at the end of DNA replication B. During replication both single and double strand nicks are responsible for supercoil relaxation whereas only double strand nicks are responsible for supercoil relaxation (terminal resolution) at the end of DNA replication C. During replication Topoisomerase II and after replication Topoisomerase I and II both carry out relaxation of the supercoils D. During replication Topoisomerase I and after replication Topoisomerase II carry out relaxation of the supercoils

A

How is DNA replication of parvovirus and adenovirus similar? A. Replication occurs by strand displacement B. A replication fork forms at the origin of replication C. None of the above D. They both require protein-linked primers

A

Which of the following is incorrect about the poxvirus DNA genome and its replication? A. all the viral replication proteins are synthesized by the virus B. The ends of the poxvirus DNA contain inverted terminal repeats (ITRs) C. Poxvirus DNA is a double stranded DNA with covalently joined ends D. Viral replication occurs in the cytoplasm of the cell

A

Which of the following is incorrect regarding Adenovirus DNA replication? A. A pre-terminal protein (pTP) binds to DNA poly and the a phosphoric group of a dGMP is bonded with a serine residue of the pTP; which acts as the primer for the DNA synthesis by bonding with the first dCMP on the template strand. B. The DNA is replicated by strand displacement C. DNA synthesis by strand displacement and DNA binding protein (DBP) coated displaced strand DNA synthesis both simultaneously participate in Adenovirus DNA replication D. The displaced strand during DNA synthesis is coated with a DNA binding protein and circularized where the inverted terminal repeats (ITRs) base pair and a new strand synthesis can initiate with the help of pre-terminal protein (pTP) using the 3' end as the template

A

Which of the following process is involved in the regulation of viral DNA synthesis? A. all of the above processes are involved in the regulation of viral DNA synthesis B. Host replication proteins are induced by early viral gene products C. Viruses must recruit host replication proteins to preferentially synthesize viral DNA D. Virally encoded early gene products often induce quiescent cells to enter the cell cycle again into the S phase

A

Which of the following is NOT a viral origin binding protein? A. Parvovirus Rep 78/68 protein B. Herpesvirus proliferative cell nuclear antigen (PCNA) protein C. Adenovirus pre-terminal protein (pTP) D. Polyomavirus (SV40) large T (LT) antigen protein

B

Which of the following protein/protein-complex is NOT associated with priming of DNA synthesis? A. Herpesvirus; UL5, 8 and 53-primase B. Parvovirus: Rep 78/68 protein C. Adenovirus: pre-terminal protein (pTP) D. SV40: DNA pol a-primase complex

B

The SV40 genome is a circular dsDNA. which statement about its replication is correct? A. Viral large T (LT) antigen protein binds and unwinds the ori B. Replication is bidirectional from a single ori C. All of the above D, Has leading and lagging strand synthesis

C

What is the function of the cellular DNA ligase IV/XRCC4 in Herpesvirus DNA replication? A. DNA ligase IV/XRCC4 is responsible for end to end DNA ligation to form concatemers during rolling circle DNA synthesis B. DNA ligase IV/XRCC4 is responsible for the terminal resolution ligation of the separated DNA strands C. DNA ligase IV/XRCC4 is responsible for circularization of the viral DNA D. DNA ligase IV/XRCC4 is responsible sealing the gaps of the replicated DNA

C

Which of the following is NOT a character associated with cellular retinoblastoma (Rb) protein? A, Rb protein is a tumor suppressor gene B. Rb protein prevents the cells to enter into the S phase of the cell cycle C. Rb protein is an oncogene D. Loss of Rb protein is associated with childhood ocular malignant tumors

C

Which of the following is NOT a mechanism of viral DNA synthesis? A. Strand displacement DNA synthesis B. Rolling circle DNA synthesis C. All of the above D. Replication fork formation at the origin of replication for DNA synthesis

C

Which of the following is the correct function of the replication factor protein Rf-C? A. Rf-C binds to 3'-OH of the DNA, PCNA, and DNA pol b B. Rf-C acts as clamp loading protein to allow clamping of PCNA onto the DNA C. All of the above are correct functions of Rf-C D. Rf-C release DNA pol-a-primase complex

C

What makes poxvirus DNA replication different from all of the other viruses? A. The complete replication machinery is encoded by the viral genome B. DNA synthesis occurs in the nucleus C. DNA synthesis occurs by strand displacement D. None of the above

D

Which of the following is NOT function of the large T (LT) antigen protein in SV40 DNA replication A. In presence of ATP, LT forms header and binds to the SV40 origin of replication and undergo conformational changes to denature the DNA strands B. LT protein in association with Rp-A, single stranded binding protein and Topoisomerase I shows helices activity and unwinds SV40 DNA C. Two LT protein hexameters ind on the opposite end of the SV40 origin of replication D. LT protein shows helices activity and unwinds the SV40 DNA in an ATP dependent manner

D

Which of the following mechanism explains the abrogation of cellular Rb protein by viral proteins A. Viral protein like E1A binds to Rb protein and induce phosphorylation which dissociate Rb from E2f and Dp protein leading to transcriptional activation B. Viral proteins like E1A competitively binds to Rb protein; which in turn binds to transcription factor E2F and Dp to form E1A, Rb, E2F, Dp complex which induce transcription C. Viral protein like E1A binds to Rb and recruit histone deacetylases which lead to transcriptional activation D. Viral protein like E1A competitively binds to Rb protein which removes Rb protein bound to transcription factor E2f and Dp and Rb protein free E2f and Dp induce transcription

D