1a5b
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CRYO-CRYSTALLOGRAPHY OF A TRUE SUBSTRATE, INDOLE-3-GLYCEROL PHOSPHATE, BOUND TO A MUTANT (ALPHA D60N) TRYPTOPHAN SYNTHASE ALPHA2BETA2 COMPLEX REVEALS THE CORRECT ORIENTATION OF ACTIVE SITE ALPHA GLU 49
OverviewOverview
The reversible cleavage of indole-3-glycerol by the alpha-subunit of, tryptophan synthase has been proposed to be catalyzed by alphaGlu49 and, alphaAsp60. Although previous x-ray crystallographic structures of the, tryptophan synthase alpha2beta2 complex showed an interaction between the, carboxylate of alphaAsp60 and the bound inhibitor indole-3-propanol, phosphate, the carboxylate of alphaGlu49 was too distant to play its, proposed role. To clarify the structural and functional roles of, alphaGlu49, we have determined crystal structures of a mutant (alphaD60N), alpha2beta2 complex in the presence and absence of the true substrate, indole-3-glycerol phosphate. The enzyme in the crystal cleaves, indole-3-glycerol phosphate very slowly at room temperature but not under, cryo-conditions of ... [(full description)]
About this StructureAbout this Structure
1A5B is a [Protein complex] structure of sequences from [Salmonella typhimurium] with K, IGP and PLP as [ligands]. Active as [Tryptophan synthase], with EC number [4.2.1.20]. Structure known Active Sites: S1 and S2. Full crystallographic information is available from [OCA].
ReferenceReference
Cryo-crystallography of a true substrate, indole-3-glycerol phosphate, bound to a mutant (alphaD60N) tryptophan synthase alpha2beta2 complex reveals the correct orientation of active site alphaGlu49., Rhee S, Miles EW, Davies DR, J Biol Chem. 1998 Apr 10;273(15):8553-5. PMID:9535826 [[Category: mutation at position 60 (asp --> asn) in the a-subunit]]
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