Question

Sigma factors

A) Compete to interact with RNA polymerase
B) Form homodimers
C) Act only with the assistance of siRNA
D) Promote chromatin remodeling
E) Are histones

Answer 1

Sigma factors are proteins that assist RNA polymerase in recognizing specific promoter sequences on DNA and initiating transcription.

Step-by-step explanation:

Sigma factors are proteins that play a crucial role in gene transcription in prokaryotes. They assist RNA polymerase in recognizing specific promoter sequences on DNA and initiating transcription. Sigma factors and RNA polymerase form a complex to bind to the promoter region, allowing transcription to begin.

For example, in E. coli, a single RNA polymerase transcribes different genes by associating with different sigma factors. Each sigma factor recognizes a specific promoter sequence and promotes the transcription of genes with that sequence.

This interaction between sigma factors and RNA polymerase is crucial for the regulation of gene expression and the initiation of transcription in prokaryotes.