Question

A geneticist finds that a strain of bacteria to produces a non-functional sigma factor. Which among the following steps in transcription would most likely be first affected?

A.Assembly of RNAP onto the DNA strand

B.Identification and binding of RNAP on to the promoter sequence

C.Conversion of open initiation complex to closed initiation complex

D.Synthesis of RNA after the formation of open initiation complex

Answer 1

D

The transcription factors and RNA polymerase form a complex called the transcription initiation complex. This complex initiates transcription, and the RNA polymerase begins mRNA synthesis by matching complementary bases to the original DNA strand.