CH13 - Gene Regulation (Prokaryotes) Flashcards
repressor
a regulatory protein that prevents the operon genes from being expressed
inducer
concerning regulation of gene expression in bacteria, a molecule that turns on the transcription of the genes in an operon
regulatory protein
DNA-binding protein that binds to regulatory sequence and affects the expression of an associated gene or genes
operon
cluster or prokaryotic genes and the DNA sequences involved in their regulation
operator
A DNA regulatory sequence that controls transcription of an operon
promoter
site to which RNA polymerase binds for initiating transcription of a gene
structural gene*
a gene that codes for any RNA or protein product other than a regulatory factor
transcriptional unit
sequence in DNA that codes for single RNA, along with the sequences necessary for its transcription (contains promoter, RNA-coding sequence, and terminator)
repressible operon
operon whose expression is prevented by a repressor molecule (ex. trp operon)
inducible operon
operon whose expression is increased by an inducer molecule (ex. lac operon)
cyclic AMP (cAMP)
receptor protein that is involved in the positive regulation of operons
(inversely related to glucose; glucose is abundant, levels low)
CAP (catabolite activator protein)
protein that binds to CAP binding site on DNA (upstream of lac promoter) and bends to make promter more accessible to RNA, INCREASING TRANSCRIPTION
*synthesized in inactive form (can only bind to DNA after activated by cAMP)
coding sequence
region of DNA or RNA whose sequence determines sequence of amino acids in protein
regulatory gene
a gene involved in controlling the expression of one or more other genes (often at 5’ ends)
corepressor
a regulatory molecule that combines with repressor and activates it to shut off an operon (ex. tryptophan)
