RNA polymerase in a prokaryote is composed of several subunits. Most of these subunits are the same for the transcription of any gene, but one, known as sigma, varies considerably. Which of the following is the most probable advantage for the organism of such sigma switching?
A) It might allow the transcription process to vary from one cell to another.
B) It might allow the polymerase to recognize different promoters under certain environmental conditions.
C) It could allow the polymerase to react differently to each stop codon.
D) It could allow ribosomal subunits to assemble at faster rates.
E) It could alter the rate of translation and of exon splicing.
The ribosomes themselves are composed of RNA strands.
DNA looping permits interaction of bound NtrC and s54–RNA polymerase
Ribosomal subunits
Subunit structure of the E. coli DNA polymerase III holoenzyme
Structures of human DNA polymerase g (left) and T7 phage DNA polymerase (right) holoenzymes
Table Salt Is Composed of Sodium and Chloride