1UN1
Xyloglucan endotransglycosylase native structure.
Summary for 1UN1
Entry DOI | 10.2210/pdb1un1/pdb |
Related | 1UMZ |
Descriptor | XYLOGLUCAN ENDOTRANSGLYCOSYLASE, beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose, GOLD ION, ... (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 | 66433.19 |
Authors | Johansson, P.,Brumer, H.,Kallas, A.,Henriksson, H.,Denman, S.,Teeri, T.T.,Jones, T.A. (deposition date: 2003-09-03, release date: 2004-03-18, Last modification date: 2020-07-29) |
Primary citation | Johansson, P.,Brumer, H.,Baumann, M.,Kallas, A.,Henriksson, H.,Denman, S.,Teeri, T.T.,Jones, T.A. Crystal Structures of a Poplar Xyloglucan Endotransglycosylase Reveal Details of Transglycosylation Acceptor Binding Plant Cell, 16:874-, 2004 Cited by 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: 15020748DOI: 10.1105/TPC.020065 PDB entries with the same primary citation |
Experimental method | X-RAY DIFFRACTION (2.1 Å) |
Structure validation
Download full validation report