BIO 320 Lecture Notes - Lecture 20: Lac Repressor, Beta-Galactosidase, Hfr Cell
15 Apr 2016
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Bio 320 spring 2016 kernan qb ii gene regulation in bacteria sections f, g. A: secondary structure, none of these levels of structure, tertiary structure missense mutation, lacix, changes only the operator-binding site so that the protein no longer binds the operator, but it can still bind inducer. Iptg is a gratuitous inducer of the lac operon it induces expression even though it cannot be metabolized by the cell. Onpf is an anti-inducer: it prevents induction of the lac operon even in the presence of inducers. Propose a mechanism by which each molecule acts: with what regulatory. Onpf: the galactose derivative phenyl-b-d galactoside (phenyl-gal, structure shown) can be transported by permease and broken down by -galactosidase to give galactose, which is a usable carbon source for the cell. Despite this, wild type cells do not grow when phenyl-gal is their only carbon source.
