Transferase Versus Hydrolase: The Role of Conformational Flexibility in Reaction Specificity

Samuel H. Light, Laty A. Cahoon, Kiran V. Mahasenan, Mijoon Lee, Bill Boggess, Andrei S. Halavaty, Shahriar Mobashery, Nancy E. Freitag, Wayne F. Anderson*

*Corresponding author for this work

Research output: Contribution to journalArticle

8 Scopus citations

Abstract

Active in the aqueous cellular environment where a massive excess of water is perpetually present, enzymes that catalyze the transfer of an electrophile to a non-water nucleophile (transferases) require specific strategies to inhibit mechanistically related hydrolysis reactions. To identify principles that confer transferase versus hydrolase reaction specificity, we exploited two enzymes that use highly similar catalytic apparatuses to catalyze the transglycosylation (a transferase reaction) or hydrolysis of α-1,3-glucan linkages in the cyclic tetrasaccharide cycloalternan (CA). We show that substrate binding to non-catalytic domains and a conformationally stable active site promote CA transglycosylation, whereas a distinct pattern of active site conformational change is associated with CA hydrolysis. These findings defy the classic view of induced-fit conformational change and illustrate a mechanism by which a stable hydrophobic binding site can favor transferase activity and disfavor hydrolysis. Application of these principles could facilitate the rational reengineering of transferases with desired catalytic properties.

Original languageEnglish (US)
Pages (from-to)295-304
Number of pages10
JournalStructure
Volume25
Issue number2
DOIs
StatePublished - Feb 7 2017

Keywords

  • carbohydrate
  • hydrolase
  • non-catalytic binding
  • protein crystallography
  • surface binding sites
  • transferase
  • transglycosidase
  • transglycosylase

ASJC Scopus subject areas

  • Structural Biology
  • Molecular Biology

Fingerprint Dive into the research topics of 'Transferase Versus Hydrolase: The Role of Conformational Flexibility in Reaction Specificity'. Together they form a unique fingerprint.

  • Cite this

    Light, S. H., Cahoon, L. A., Mahasenan, K. V., Lee, M., Boggess, B., Halavaty, A. S., Mobashery, S., Freitag, N. E., & Anderson, W. F. (2017). Transferase Versus Hydrolase: The Role of Conformational Flexibility in Reaction Specificity. Structure, 25(2), 295-304. https://doi.org/10.1016/j.str.2016.12.007