BMSC 200 Lecture 11: lecture 11
Document Summary
Prokaryotes regulate cellular metabolism in response to enviroemental fluctuations: external signal is transmitted directly to the target, external signal is dected by sensor and transmitted to regulatory machinery ( signal transduction) Most signal transduction systems are two component regulatory systems. Made up of two different proteins: sensor kinase ( in cytoplasmic membrane): detects environmental signal and autophosphorylates, response regulator (in cytoplasm): dna- binding protein that regulates transcription. Also has feedback loop: terminates signal. Almost 50 different two component systems in e. coli: examples include phosphate assimilation, nitrogen metabolism, and osmotic pressure response. Some signal transduction systems have multiple regulatory elements. Some archara also have two component regulatory systems. Modified two component system used in chemotaxis to: sense temporal changes in attractants or repellents, regulate flagellar rotation. Three main steps to response to signal: step 1 sensory proteins in cytoplasmic membrane sense attractants and repellents.
