Complex Formation between Two Biosynthetic Enzymes Modifies the Allosteric Regulatory Properties of Both: AN EXAMPLE OF MOLECULAR SYMBIOSIS.

ABSTRACT: Allostery, where remote ligand binding alters protein function, is essential for the control of metabolism. Here, we have identified a highly sophisticated allosteric response that allows complex control of the pathway for aromatic amino acid biosynthesis in the pathogen Mycobacterium tuberculosis. This response is mediated by an enzyme complex formed by two pathway enzymes: chorismate mutase (CM) and 3-deoxy-d-arabino-heptulosonate 7-phosphate synthase (DAH7PS). Whereas both enzymes are active in isolation, the catalytic activity of both enzymes is enhanced, and in particular that of the much smaller CM is greatly enhanced (by 120-fold), by formation of a hetero-octameric complex between CM and DAH7PS. Moreover, on complex formation M. tuberculosis CM, which has no allosteric response on

SUBMITTER: Blackmore NJ 

PROVIDER: S-EPMC4505062 | biostudies-literature | 2015 Jul

REPOSITORIES: biostudies-literature