What Would the Result Be If a Specific Sigma Subunit

Multiple Choice

What would the result be if a specific sigma subunit were mutated?

A) Nothing would result: sigma is not essential.
B) RNA polymerase would still bind at specific sites,but elongation would fail.
C) RNA polymerase would fail to initiate transcription at the promoter specific to the sigma subunit.
D) The core enzyme would not be stable.