2BU3

Acyl-enzyme intermediate between Alr0975 and glutathione at pH 3.4

Summary for 2BU3

• Entry DOI: 10.2210/pdb2bu3/pdb
• Related: 2BTW
• Descriptor: ALR0975 PROTEIN, GAMMA-GLUTAMYLCYSTEINE, CHLORIDE ION, ... (5 entities in total)
• Functional Keywords: phytochelatin synthase, pcs, alr0975, acyl-enzyme intermediate, nostoc, glutathione metabolism, cysteine protease, transferase
• Biological source: ANABAENA SP. (NOSTOC SP. PCC 7120)
• Total number of polymer chains: 2
• Total formula weight: 59526.05

Authors

Vivares, D.,Arnoux, P.,Pignol, D. (deposition date: 2005-06-08, release date: 2005-12-14, Last modification date: 2024-11-06)

Primary citation

Vivares, D.,Arnoux, P.,Pignol, D.
A Papain-Like Enzyme at Work: Native and Acyl- Enzyme Intermediate Structures in Phytochelatin Synthesis.
Proc.Natl.Acad.Sci.USA, 102:18848-, 2005

PubMed Abstract: Phytochelatin 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.

PubMed: 16339904
DOI: 10.1073/PNAS.0505833102

Experimental method

X-RAY DIFFRACTION (1.4 Å)