The N253F mutant structure of trehalose synthase from Deinococcus radiodurans reveals an open active-site topology

Acta Crystallogr F Struct Biol Commun. 2017 Nov 1;73(Pt 11):588-594. doi: 10.1107/S2053230X17014303. Epub 2017 Oct 20.


Trehalose synthase (TS) catalyzes the reversible conversion of maltose to trehalose and belongs to glycoside hydrolase family 13 (GH13). Previous mechanistic analysis suggested a rate-limiting protein conformational change, which is probably the opening and closing of the active site. Consistently, crystal structures of Deinococcus radiodurans TS (DrTS) in complex with the inhibitor Tris displayed an enclosed active site for catalysis of the intramoleular isomerization. In this study, the apo structure of the DrTS N253F mutant displays a new open conformation with an empty active site. Analysis of these structures suggests that substrate binding induces a domain rotation to close the active site. Such a substrate-induced domain rotation has also been observed in some other GH13 enzymes.

Keywords: X-ray crystallography; conformational change; domain rotation; enzyme mechanism; glycoside hydrolase family 13; trehalose synthase.

MeSH terms

  • Catalytic Domain
  • Crystallography, X-Ray
  • Deinococcus / enzymology*
  • Glucosyltransferases / chemistry*
  • Glucosyltransferases / genetics*
  • Models, Molecular
  • Mutation*
  • Protein Conformation
  • Substrate Specificity


  • Glucosyltransferases
  • trehalose synthase