Substrate induction
As substrate induction a is enzyme induction referred to, wherein the substrate of a metabolic pathway as inductor acts.
This form of gene regulation was first described by F. Jacob and J. Monod in bacteria and explained using the lac operon model . Here, a substrate such as leads lactose by binding to a repressor to its conformational change . This detaches it from the DNA and is thus inactivated. Until then, it had suppressed the reading ( transcription ) of a gene region and thereby hindered the formation of new enzymes that are necessary for the degradation ( catabolism ) of the substrate. With the increased formation of the appropriate enzymes now made possible, the substrate is degraded more rapidly. If its concentration has dropped as a result, the corresponding DNA segment can be blocked again by the repressor. The enzymes of this metabolic pathway are thus only formed for as long as the substrate to be broken down by them is present in greater concentration.
Web links
- Substrate induction at the lac operon. Hessian education server, accessed on September 16, 2015 .
Individual evidence
- ↑ F. Jacob & J. Monod (1961): Genetic regulatory mechanisms in the synthesis of proteins. In: J. Mol. Biol. Vol. 3, pp. 318-356. PMID 13718526
literature
- Lubert Stryer: Biochemistry , 4th edition, Spectrum, Heidelberg - Berlin - Oxford 1996. ISBN 978-3860253465 . Pp. 995-1019, (36. The control of gene expression in prokaryotes )