Download MendeleyCrystal structures of 1-aminocyclopropane-1-carboxylate (ACC) synthase in complex with aminoethoxyvinylglycine and pyridoxal-5'-phosphate provide new insight into catalytic mechanisms
Huai, Q., Xia, Y., Chen, Y., Callahan, B., Li, N., Ke, H.(2001) J Biol Chem 276: 38210-38216
- PubMed: 11431475
- DOI: https://doi.org/10.1074/jbc.M103840200
- Primary Citation of Related Structures:
1IAX, 1IAY - PubMed Abstract:
The structures of tomato 1-aminocyclopropane-1-carboxylate synthase (ACS) in complex with either cofactor pyridoxal-5'-phosphate (PLP) or both PLP and inhibitor aminoethoxyvinylglycine have been determined by x-ray crystallography. The structures showed good conservation of the catalytic residues, suggesting a similar catalytic mechanism for ACS and other PLP-dependent enzymes. However, the proximity of Tyr152 to the C-gamma-S bond of model substrate S-adenosylmethionine implies its critical role in the catalysis. The concerted accomplishment of catalysis by cofactor PLP and a protein residue, as proposed on the basis of the ACS structures in this paper, may represent a general scheme for the diversity of PLP-dependent catalyses. PLP-dependent enzymes have been categorized into four types of folds. A structural comparison revealed that a core fragment of ACS in fold type I is superimposable over tryptophan synthase beta subunit in fold type II and mouse ornithine decarboxylase in fold type III, thus suggesting a divergent evolution of PLP-dependent enzymes.
Organizational Affiliation:
Department of Biochemistry and Biophysics and Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, 27599-7260, USA.
