Bacterial Gene Regulation and Enzyme Control

A set of vocabulary flashcards based on lecture notes regarding prokaryotic gene regulation, operons, regulons, and enzyme activity control.

Transcription (Regulation)

The most prominent control method among prokaryotes for regulating gene expression.

Operon

A regulatory region that controls two or more genes transcribed from a single promoter.

Regulon

A series of genes or operons that are all controlled by the same regulatory protein, allowing for global regulation of a large number of genes.

Sigma factors

Proteins that allow RNAP to recognize different promoters, such as those involved in heat shock or endospore formation.

Diauxic growth of E. coli

A growth pattern where $E.\text{ coli}$ uses glucose first when both glucose and lactose are present, followed by lactose utilization.

Positive control

A form of regulation where a regulatory protein binds upstream of the promoter at an activator binding site to increase transcription initiation.

Negative control

A form of regulation where a regulatory protein (represser) binds downstream of the promoter at an operator to inhibit transcription initiation by blocking RNAP.

Attenuation

A transcriptional control method coupled to translation that is based on DNA sequence/folding and ribosome behavior, such as in the tryptophan (trp) biosynthesis operon.

Leader region

A region downstream of the promoter in attenuation that is transcribed and translated to make a small leader peptide.

Two-Component Phosphorelay System

A system that links outside events to the inside of the cell using a sensor in the CM and a response-regulator in the cytoplasm that receives a signal ($PO_4$).

Translational Control

Also known as post-transcriptional control, this method involves small non-coding RNA molecules binding to mRNA in response to a signal.

Allostery

Enzyme regulation where an end product or small molecule binds to an allosteric site to change the enzyme's conformation so the substrate can no longer bind to the active site.

Covalent modification

A process where chemical groups are added to or removed from enzymes to turn them on or off based on changing conditions.