1FCJ
CRYSTAL STRUCTURE OF OASS COMPLEXED WITH CHLORIDE AND SULFATE
Summary for 1FCJ
Entry DOI | 10.2210/pdb1fcj/pdb |
Related | 1D6S 1OAS |
Descriptor | O-ACETYLSERINE SULFHYDRYLASE, SULFATE ION, CHLORIDE ION, ... (5 entities in total) |
Functional Keywords | homodimer, lyase |
Biological source | Salmonella typhimurium |
Total number of polymer chains | 4 |
Total formula weight | 139396.32 |
Authors | Burkhard, P.,Tai, C.,Jansonius, J.N.,Cook, P.F. (deposition date: 2000-07-18, release date: 2000-10-18, Last modification date: 2025-03-26) |
Primary citation | Burkhard, P.,Tai, C.H.,Jansonius, J.N.,Cook, P.F. Identification of an allosteric anion-binding site on O-acetylserine sulfhydrylase: structure of the enzyme with chloride bound. J.Mol.Biol., 303:279-286, 2000 Cited by PubMed Abstract: A new crystal structure of O-acetylserine sulfhydrylase (OASS) has been solved with chloride bound at an allosteric site and sulfate bound at the active site. The bound anions result in a new "inhibited" conformation, that differs from the "open" native or "closed" external aldimine conformations. The allosteric site is located at the OASS dimer interface. The new inhibited structure involves a change in the position of the "moveable domain" (residues 87-131) to a location that differs from that in the open or closed forms. Formation of the external aldimine with substrate is stabilized by interaction of the alpha-carboxyl group of the substrate with a substrate-binding loop that is part of the moveable domain. The inhibited conformation prevents the substrate-binding loop from interacting with the alpha-carboxyl group, and hinders formation of the external Schiff base and thus subsequent chemistry. Chloride may be an analog of sulfide, the physiological inhibitor. Finally, these results suggest that OASS represents a new class of PLP-dependent enzymes that is regulated by small anions. PubMed: 11023792DOI: 10.1006/jmbi.2000.4109 PDB entries with the same primary citation |
Experimental method | X-RAY DIFFRACTION (2 Å) |
Structure validation
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