Structural, Mutagenic and In Silico Studies of Xyloglucan Fucosylation in Arabidopsis thaliana Suggest a Water-Mediated Mechanism

Michael Crowley, Petri Alahuhta, Vladimir Lunin, Yannick Bomble, Michael Himmel, Vivek Bharadwaj, Breeanna Urbanowicz, Maria Pena, Shuo Wang, Jeong-Yeh Yang, Sami Tuomivaara, Kelley Moremen, William York

Research output: Contribution to journalArticlepeer-review

51 Scopus Citations

Abstract

The mechanistic underpinnings of the complex process of plant polysaccharide biosynthesis are poorly understood, largely because of the resistance of glycosyltransferase (GT) enzymes to structural characterization. In Arabidopsis thaliana, a glycosyl transferase family 37 (GT37) fucosyltransferase 1 (AtFUT1) catalyzes the regiospecific transfer of terminal 1,2-fucosyl residues to xyloglucan side chains – a key step in the biosynthesis of fucosylated sidechains of galactoxyloglucan. We unravel the mechanistic basis for fucosylation by AtFUT1 with a multipronged approach involving protein expression, X-ray crystallography, mutagenesis experiments and molecular simulations. Mammalian cell culture expressions enable the sufficient production of the enzyme for X-ray crystallography, which reveals the structural architecture of AtFUT1 in complex with bound donor and acceptor substrate analogs. The lack of an appropriately positioned active site residue as a catalytic base leads us to propose an atypical water-mediated fucosylation mechanism facilitated by an H-bonded network, which is corroborated by mutagenesis experiments as well as detailed atomistic simulations.

Original languageAmerican English
Pages (from-to)931-949
Number of pages19
JournalPlant Journal
Volume91
Issue number6
DOIs
StatePublished - Sep 2017

Bibliographical note

Publisher Copyright:
© 2017 The Authors The Plant Journal © 2017 John Wiley & Sons Ltd

NREL Publication Number

  • NREL/JA-2700-67766

Keywords

  • Arabidopsis thaliana
  • fucosylation
  • fucosyltransferase
  • hemicellulose synthesis
  • reaction mechanism

Fingerprint

Dive into the research topics of 'Structural, Mutagenic and In Silico Studies of Xyloglucan Fucosylation in Arabidopsis thaliana Suggest a Water-Mediated Mechanism'. Together they form a unique fingerprint.

Cite this