Gene regulation in Bacteria

Gene regulation

a phenomenon in which the level of gene expression can vary under different conditions

Constitutive genes

a gene that is not regulated and has essentially constant levels of expression over time

Regulatory genes

genes who’s products interact with DNA and affect transcription or translation

Regulatory proteins

proteins that bind to DNA and affect the rate of transcription or translation

Negative control

transcriptional regulation by a repressor

repressor

regulatory protein that inhibits transcription

postive control

transcriptional regulation by an activator

Activator

regulatory portion that increases the rate of transcription

effector molecules

does not directly bind to the DNA; binds to regulatory protein at the allosteric site and causes a conformational change that influences if the protein can bind to the DNA

Inducible genes

genes that are regulated by an inducer

Inducer

effector molecule that increases the rate of transcription

repressible genes

genes that are regulated by a corepressor or inhibitor and causes the rate of transcription to decrease

corepressor

effector molecule that binds a repressor and causes it to bind to the DNA

Inhibitor

effector molecule that binds an activator and causes it fall off of the DNA

Operon

an arrangement in DNA in which 2 or more genes are under the transcriptional control of a single promoter

Polycistronic mRNA

an mRNA transcribed from an operon that encodes two or more proteins

translational repressors

proteins that bind to mRNA and inhibit its ability to be translated

Antisense RNA

an RNA strand that is complementary to a strand of mRNA

Feedback inhibition

the final product of a metabolic pathway inhibits an enzyme that acts early in the pathway

Posttranslational covalent modification

covalent attachment of a molecule to a protein after it has been synthesized via ribosomes

Riboswitch

genetic regulation in which an RNA molecule can exist in two different secondary conformations