2bu3
From Proteopedia
Acyl-enzyme intermediate between Alr0975 and glutathione at pH 3.4
Structural highlights
FunctionEvolutionary ConservationCheck, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedPhytochelatin synthase (PCS) is a key enzyme for heavy-metal detoxification in plants. PCS catalyzes the production of glutathione (GSH)-derived peptides (called phytochelatins or PCs) that bind heavy-metal ions before vacuolar sequestration. The enzyme can also hydrolyze GSH and GS-conjugated xenobiotics. In the cyanobacterium Nostoc, the enzyme (NsPCS) contains only the catalytic domain of the eukaryotic synthase and can act as a GSH hydrolase and weakly as a peptide ligase. The crystal structure of NsPCS in its native form solved at a 2.0-A resolution shows that NsPCS is a dimer that belongs to the papain superfamily of cysteine proteases, with a conserved catalytic machinery. Moreover, the structure of the protein solved as a complex with GSH at a 1.4-A resolution reveals a gamma-glutamyl cysteine acyl-enzyme intermediate stabilized in a cavity of the protein adjacent to a second putative GSH binding site. GSH hydrolase and PCS activities of the enzyme are discussed in the light of both structures. A papain-like enzyme at work: native and acyl-enzyme intermediate structures in phytochelatin synthesis.,Vivares D, Arnoux P, Pignol D Proc Natl Acad Sci U S A. 2005 Dec 27;102(52):18848-53. Epub 2005 Dec 9. PMID:16339904[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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