1xrs
Crystal structure of Lysine 5,6-Aminomutase in complex with PLP, cobalamin, and 5'-deoxyadenosine
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OverviewOverview
Lysine 5,6-aminomutase is an adenosylcobalamin and, pyridoxal-5'-phosphate-dependent enzyme that catalyzes a 1,2 rearrangement, of the terminal amino group of dl-lysine and of l-beta-lysine. We have, solved the x-ray structure of a substrate-free form of, lysine-5,6-aminomutase from Clostridium sticklandii. In this structure, a, Rossmann domain covalently binds pyridoxal-5'-phosphate by means of lysine, 144 and positions it into the putative active site of a neighboring, triosephosphate isomerase barrel domain, while simultaneously positioning, the other cofactor, adenosylcobalamin, approximately 25 A from the active, site. In this mode of pyridoxal-5'-phosphate binding, the cofactor acts as, an anchor, tethering the separate polypeptide chain of the Rossmann domain, to the triosephosphate isomerase barrel domain. Upon substrate binding and, transaldimination of the lysine-144 linkage, the Rossmann domain would be, free to rotate and bring adenosylcobalamin, pyridoxal-5'-phosphate, and, substrate into proximity. Thus, the structure embodies a locking mechanism, to keep the adenosylcobalamin out of the active site and prevent radical, generation in the absence of substrate.
About this StructureAbout this Structure
1XRS is a Protein complex structure of sequences from Clostridium sticklandii with B12, PLP and 5AD as ligands. Active as Beta-lysine 5,6-aminomutase, with EC number 5.4.3.3 Full crystallographic information is available from OCA.
ReferenceReference
A locking mechanism preventing radical damage in the absence of substrate, as revealed by the x-ray structure of lysine 5,6-aminomutase., Berkovitch F, Behshad E, Tang KH, Enns EA, Frey PA, Drennan CL, Proc Natl Acad Sci U S A. 2004 Nov 9;101(45):15870-5. Epub 2004 Oct 28. PMID:15514022
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