1UMZ

Xyloglucan endotransglycosylase in complex with the xyloglucan nonasaccharide XLLG.

Summary for 1UMZ

• Entry DOI: 10.2210/pdb1umz/pdb
• Related: 1UN1
• Descriptor: XYLOGLUCAN ENDOTRANSGLYCOSYLASE, beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose, alpha-D-xylopyranose-(1-6)-beta-D-glucopyranose-(1-4)-[beta-D-galactopyranose-(1-2)-alpha-D-xylopyranose-(1-6)]beta-D-glucopyranose-(1-4)-beta-D-glucopyranose, ... (4 entities in total)
• Functional Keywords: glycoside hydrolase, xet, xth, xeh, transglycosylation, xyloglucan, transferase, glycosyltransferase
• Biological source: POPULUS TREMULA (EUROPEAN ASPEN)
• Total number of polymer chains: 2
• Total formula weight: 68097.84

Authors

Johansson, P.,Brumer, H.,Kallas, A.M.,Henriksson, H.,Denman, S.E.,Teeri, T.T.,Jones, T.A. (deposition date: 2003-09-03, release date: 2004-03-18, Last modification date: 2023-12-13)

Primary citation

Johansson, P.,Brumer, H.,Baumann, M.J.,Kallas, A.M.,Henriksson, H.,Denman, S.E.,Teeri, T.T.,Jones, T.A.
Crystal Structures of a Poplar Xyloglucan Endotransglycosylase Reveal Details of Transglycosylation Acceptor Binding
Plant Cell, 16:874-, 2004

PubMed Abstract: Xyloglucan endotransglycosylases (XETs) cleave and religate xyloglucan polymers in plant cell walls via a transglycosylation mechanism. Thus, XET is a key enzyme in all plant processes that require cell wall remodeling. To provide a basis for detailed structure-function studies, the crystal structure of Populus tremula x tremuloides XET16A (PttXET16A), heterologously expressed in Pichia pastoris, has been determined at 1.8-A resolution. Even though the overall structure of PttXET16A is a curved beta-sandwich similar to other enzymes in the glycoside hydrolase family GH16, parts of its substrate binding cleft are more reminiscent of the distantly related family GH7. In addition, XET has a C-terminal extension that packs against the conserved core, providing an additional beta-strand and a short alpha-helix. The structure of XET in complex with a xyloglucan nonasaccharide, XLLG, reveals a very favorable acceptor binding site, which is a necessary but not sufficient prerequisite for transglycosylation. Biochemical data imply that the enzyme requires sugar residues in both acceptor and donor sites to properly orient the glycosidic bond relative to the catalytic residues.

PubMed: 15020748
DOI: 10.1105/TPC.020065

Experimental method

X-RAY DIFFRACTION (1.8 Å)