The most critical difference between global nucleotide excision repair (NER) and transcription-coupled repair (TCR) is:
A. the initiation step; in NER the XPC protein recognizes the damage but in TCR it is the RNA polymerase that recognizes the damage.
B. the excision step; NER uses UvrC (exinuclease) to nick the DNA but TCR uses the AP endonuclease.
C. the removal step; NER uses UvrD (helicase) to unwind and release the damaged strand but in TCR the damaged strand is degraded by Pol I.
D. the final step; NER uses Pol I and ligase to fill the gap but TCR uses Pol III and ligase.
E. None of the choices given is correct.
With regard to DNA topology, which of the following is not a continuous deformation?
A. conformational changes due to stretching
B. conformational changes due to thermal motion
C. conformational changes due to interaction with proteins
D. conformational changes due to interaction with molecules other than proteins
E. conformational changes due to DNA strand breakage
Which of the following is not a component of a yeast three-hybrid analysis?
A. a fusion protein of LexA, which binds the reporter construct, and MS2, which specifically binds an RNA tag that has been added to every RNA produced by the plasmid library
B. a plasmid library that contains random sequences from the genome tagged with a unique hairpin sequence that MS2 will bind
C. a reporter construct that contains a LexA operator (binding site) and a reporter gene; activation of the reporter gene is either required for growth of the bacteria or catalyzes a reaction that forms a colored product
D. a fusion protein containing the protein of interest fused to the activation domain that will activate transcription of the reporter gene when bound
E. a fusion protein of the protein of interest and two tagsthe calmodulin binding site and protein A
Which of the following is not an essential component of the eukaryotic elongation stage of translation?
A. magnesium ion
B. eIF3
C. GTP
D. aminoacyl-tRNAs
Which of the following is not a component of the bacterial RNA polymerase core enzyme?
A. subunit
B. subunit
C. subunit
D. subunit
E. subunit '
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