BIO 325 Chapter Notes - Chapter 15: Allolactose, Catabolite Repression, Conformational Change
Document Summary
Rna polymerase is the enzyme crucial for prokaryotic transcription. The sigma factor allows it to recognize promoters, and the rho proteins terminates transcription for some genes. There"s (cid:374)o (cid:374)u(cid:272)leus or a(cid:374)y (cid:373)e(cid:373)(cid:271)ra(cid:374)e to e(cid:374)(cid:272)lose the (cid:271)a(cid:272)terial (cid:272)hro(cid:373)oso(cid:373)e, so tra(cid:374)slatio(cid:374) (cid:272)an begin while transcription is still happening. Many bacterial mrnas are polycistronic: it has multiple open reading frames. Each open reading frame in the transcript has its own ribosome binding site. Prokaryotic gene expression can be regulated at transcription initiation, elongation, or termination, mrna stability, translation initiation, or protein stability or activity. Inducible regulation: gene control where transcription occurs only in the presence of an inducer, repressible regulation, gene control where transcription occurs only in the absence of a repressor. Induction: process by which a specific molecule stimulates synthesis of a given protein, a signal induces expression of a gene or set of genes.
