MICRB316 Lecture Notes - Lecture 16: Dna-Binding Domain, Nucleoprotein, Cooperative Binding
20 Mar 2016
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No unifying stimulus, can"t predict at every promoter what lrp will do- can be repressor/activator, respond/not respond to leu. Involved in biosynthetic gene synthesis seen mostly in poor medium- represses genes for protein in rich media. Feast or famine regulator- determines what the cell does with low nutrient/high nutrient. In rich medium lrp is at its lowest. In poor medium: lrp is at its highest- usually works as an activator of biosynthesis genes and blocks genes for enzymes that break down nutrients (catabolic enzymes are not needed if there are not that many nutrients). Example of gene regulation: lactose utilization genes, leucine biosynthesis, regulation of imbrae, etc . Copy number is max at log phase and dependent on quality of growth medium . In minimal media- 3-4x more lrp- depends on amount of. Aa available to the cell and carbon source type. Lrp has modular organization: n-hth dna binding domain c- where the leu binds/response (dimerization domain).
