MICRB316 Lecture Notes - Lecture 14: Regulon, Repressor Lexa, Sos Response
Document Summary
Networks are interlinked control systems; some are complex) Not just 1 or 2 regulators affecting a single gene or operon, but many transcripts. Should not be understood as independent control circuits, but rather a global network, affecting many different genes. The following examples illustrate that almost nothing happens in a celll without affecting the other cellular activities and reactions. Operon a number of genes (often related in function) encoded as a transcriptional unit and transcriptionally co-regulated. Typical of prokaryotes (polycistronic arrangement) e. g. metabolic pathways (galetk, arabad, laczya) Regulon organization of several independent operons, controlled in a coordinated way. Does not mean genes are always expressed in a parallel manner (1. extent of reg varies and 2. activation of one operon/gene can be concurrent with repression of others by same regulator. e. g. heat shock; sos; lrp) Modulon describes independent operons that belong to different regulons but respond to a common regulator.