5t6m
From Proteopedia
(Difference between revisions)
| Line 12: | Line 12: | ||
== Function == | == Function == | ||
[[http://www.uniprot.org/uniprot/TRPB1_PYRFU TRPB1_PYRFU]] The beta subunit is responsible for the synthesis of L-tryptophan from indole and L-serine (By similarity). | [[http://www.uniprot.org/uniprot/TRPB1_PYRFU TRPB1_PYRFU]] The beta subunit is responsible for the synthesis of L-tryptophan from indole and L-serine (By similarity). | ||
| + | <div style="background-color:#fffaf0;"> | ||
| + | == Publication Abstract from PubMed == | ||
| + | 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)-beta-methyltryptophan. Surprisingly, beta-substitution occurs in vitro with a 3.4-fold higher catalytic efficiency for Ser over Thr using saturating indole, despite a >82000-fold preference for Ser in direct competition using IGP. Structural data identify a novel product binding site, and kinetic experiments clarify the atypical mechanism of specificity: Thr binds efficiently but decreases the affinity for indole and disrupts the allosteric signaling that regulates the catalytic cycle. | ||
| + | |||
| + | Tryptophan Synthase Uses an Atypical Mechanism To Achieve Substrate Specificity.,Buller AR, van Roye P, Murciano-Calles J, Arnold FH Biochemistry. 2016 Dec 27;55(51):7043-7046. doi: 10.1021/acs.biochem.6b01127., Epub 2016 Dec 13. PMID:27935677<ref>PMID:27935677</ref> | ||
| + | |||
| + | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | ||
| + | </div> | ||
| + | <div class="pdbe-citations 5t6m" style="background-color:#fffaf0;"></div> | ||
| + | == References == | ||
| + | <references/> | ||
__TOC__ | __TOC__ | ||
</StructureSection> | </StructureSection> | ||
Revision as of 08:21, 18 January 2017
Structure of the tryptophan synthase b-subunit from Pyroccus furiosus with b-methyltryptophan non-covalently bound
| |||||||||||
