5KX6 image
Entry Detail
PDB ID:
5KX6
Keywords:
Title:
The structure of Arabidopsis thaliana FUT1 Mutant R284K in complex with GDP
Biological Source:
Source Organism:
Host Organism:
PDB Version:
Deposition Date:
2016-07-20
Release Date:
2016-09-28
Method Details:
Experimental Method:
Resolution:
2.20 Å
R-Value Free:
0.32
R-Value Work:
0.25
R-Value Observed:
0.25
Space Group:
P 1 21 1
Macromolecular Entities
Polymer Type:polypeptide(L)
Description:Galactoside 2-alpha-L-fucosyltransferase
Chain IDs:A, B
Chain Length:476
Number of Molecules:2
Biological Source:Arabidopsis thaliana
Primary Citation
Structural, mutagenic and in silico studies of xyloglucan fucosylation in Arabidopsis thaliana suggest a water-mediated mechanism.
Plant J. 91 931 949 (2017)
PMID: 28670741 DOI: 10.1111/tpj.13628

Abstact

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.

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