Transcriptional Regulation in Bacteria

These flashcards cover key vocabulary terms related to transcriptional regulation in bacteria, specifically focusing on mechanisms involving the lac operon and trp operon.

Transcription

The process of copying a DNA sequence into an RNA sequence.

Transcriptional regulation

The control over whether or not transcription occurs and to what extent a gene is transcribed.

Sigma factors

Proteins that influence the initiation of transcription by recognizing promoter sequences in bacteria.

Constitutively expressed genes

Genes that are constantly expressed and required for normal cell metabolism and function.

Holoenzyme

The complete RNA polymerase complex that scans DNA for the promoter region to initiate transcription.

Operon

A regulatory unit consisting of a few protein-coding genes under the control of one promoter, common in bacterial genomes.

Inducer

An effector molecule that increases transcription by binding to activators.

Inhibitor

An effector molecule that decreases transcription by binding to repressors, also known as a corepressor.

Lac repressor

A protein that inhibits transcription of the lac operon in the absence of lactose.

Catabolite Activator Protein (CAP)

An activator that binds to DNA to increase transcription under low glucose conditions.

trp repressor

A protein that binds to the operator of the trp operon to inhibit transcription in the presence of tryptophan.

Allolactose

A compound that binds to the lac repressor, preventing it from inhibiting the transcription of the lac operon.