4-3_-_Transcriptional_regulation

Transcriptional Regulation

The control of gene expression at the level of transcription, crucial for how cells adapt to their environments.

Transcription Factors

DNA-binding regulatory proteins that are essential for the regulation of transcription initiation.

Activators

Transcription factors that promote transcription by recruiting RNA polymerase to the promoter.

Repressors

Transcription factors that inhibit transcription, often by preventing RNA polymerase from binding to DNA.

Allosteric Regulation

A type of regulation where the binding of a small molecule alters the activity of a regulatory protein, impacting its ability to bind DNA.

Inducible System

A system that is off by default but can be activated under specific conditions.

Repressible System

A system that is on by default but can be turned off when certain conditions prevail.

Lac Operon

A set of genes in E. coli responsible for the metabolism of lactose, regulated by the presence of lactose and glucose.

cAMP (Cyclic AMP)

A signaling molecule that regulates multiple cellular processes, often used in response to changes in nutrient availability.

Quorum Sensing

A process where bacteria communicate and coordinate behavior based on cell density through signaling molecules called autoinducers.

Two-Component Regulatory System

A common bacterial gene regulation system involving a sensor kinase and a response regulator.

Arginine Biosynthesis

The metabolic process regulated by ArgR repressor, which responds to levels of arginine in the cell.

Consensus Sequence

A sequence of DNA recognized by regulatory proteins, allowing specificity in transcription regulation.

Catabolite Repression

A regulatory mechanism where the presence of a preferred energy source (like glucose) suppresses the use of other sources (like lactose).

Autoinducers

Signaling molecules used in quorum sensing to communicate and induce group behaviors in microbial populations.