Biology › Section H · Gene expression and its regulation › Topic H.2

Prokaryotic transcription

Bacteria keep their DNA in the open cytoplasm, no nucleus in sight — and that one architectural fact shapes everything about how they read their genes. A single RNA polymerase finds a promoter, transcribes at forty nucleotides per second, and can produce messages covering several genes at once, with ribosomes already translating each message before the polymerase has even finished writing it. This topic walks the full cycle: initiation, elongation, and the two rival ways a bacterium ends a transcript.