Catalytic Mechanism of the Tryptophan Synthase α2β2 Complex
نویسندگان
چکیده
منابع مشابه
The tryptophan synthase α2β2 complex: a model for substrate channeling, allosteric communication, and pyridoxal phosphate catalysis.
I reflect on my research on pyridoxal phosphate (PLP) enzymes over fifty-five years and on how I combined research with marriage and family. My Ph.D. research with Esmond E. Snell established one aspect of PLP enzyme mechanism. My postdoctoral work first with Hans L. Kornberg and then with Alton Meister characterized the structure and function of another PLP enzyme, l-aspartate β-decarboxylase....
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To probe the structural and functional roles of activesite residues in the tryptophan synthase a2b2 complex from Salmonella typhimurium, we have determined the effects of mutation of His in the b subunit. His is located adjacent to b subunit Lys, which forms an internal aldimine with the pyridoxal phosphate and catalyzes the abstraction of the a-proton of L-serine. The replacement of His by leu...
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heteropoly acids (hpa) and their salts have advantages as catalysts which make them both economically and environmentally attractive, strong br?nsted acidity, exhibiting fast reversible multi-electron redox transformations under rather mild conditions, very high solubility in polar solvents, fairly high thermal stability in the solid states, and efficient oxidizing ability, so that they are imp...
15 صفحه اولTryptophan Synthase Uses an Atypical Mechanism To Achieve Substrate Specificity.
Tryptophan synthase (TrpS) catalyzes the final steps in the biosynthesis of l-tryptophan from l-serine (Ser) and indole-3-glycerol phosphate (IGP). We report that native TrpS can also catalyze a productive reaction with l-threonine (Thr), leading to (2S,3S)-β-methyltryptophan. Surprisingly, β-substitution occurs in vitro with a 3.4-fold higher catalytic efficiency for Ser over Thr using saturat...
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Cellulose synthesis is driven by large plasma membrane-inserted protein complexes, which in plants have 6-fold symmetry. In Arabidopsis (Arabidopsis thaliana), functional cellulose synthesis complexes (CSCs) are composed of at least three different cellulose synthase catalytic subunits (CESAs), but the actual ratio of the CESA isoforms within the CSCs remains unresolved. In this work, the stoic...
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ژورنال
عنوان ژورنال: Journal of Biological Chemistry
سال: 1999
ISSN: 0021-9258
DOI: 10.1074/jbc.274.44.31189