2lgs

Publication Abstract from PubMed

Bacterial glutamine synthetase (GS; EC 6.3.1.2) was previously shown to be inhibited by nine end products of glutamine metabolism. Here we present four crystal structures of GS, complexed with the substrate Glu and with each of three feedback inhibitors. The GS of the present study is from Salmonella typhimurium, with Mn2+ ions bound, and is fully unadenylylated. From Fourier difference maps, we find that L-serine, L-alanine, and glycine bind at the site of the substrate L-glutamate. In our model, these four amino acids bind with the atoms they share in common (the "main chain" +NH3-CH-COO-) in the same positions. Thus on the basis of our x-ray work, glycine, alanine, and serine appear to inhibit GS-Mn by competing with the substrate glutamate for the active site.

Feedback inhibition of fully unadenylylated glutamine synthetase from Salmonella typhimurium by glycine, alanine, and serine.,Liaw SH, Pan C, Eisenberg D Proc Natl Acad Sci U S A. 1993 Jun 1;90(11):4996-5000. PMID:8099447^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.