Taxonomic group: plant / Streptophyta
(Phylum: Streptophyta)
Organ / tissue: leaf
Publication DOI: 10.1105/tpc.009837Journal NLM ID: 9208688Publisher: Rockville, MD: American Society of Plant Physiologists
Correspondence: wdreiter
uconnvm.uconn.edu
Institutions: Department of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana 47907-1155, Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut 06269
Xyloglucans are the principal glycans that interlace cellulose microfibrils in most flowering plants. The mur3 mutant of Arabidopsis contains a severely altered structure of this polysaccharide because of the absence of a conserved α-L-fucosyl-(1→2)-β-D-galactosyl side chain and excessive galactosylation at an alternative xylose residue. Despite this severe structural alteration, mur3 plants were phenotypically normal and exhibited tensile strength in their inflorescence stems comparable to that of wild-type plants. The MUR3 gene was cloned positionally and shown to encode a xyloglucan galactosyltransferase that acts specifically on the third xylose residue within the XXXG core structure of xyloglucan. MUR3 belongs to a large family of type-II membrane proteins that is evolutionarily conserved among higher plants. The enzyme shows sequence similarities to the glucuronosyltransferase domain of exostosins, a class of animal glycosyltransferases that catalyze the synthesis of heparan sulfate, a glycosaminoglycan with numerous roles in cell differentiation and development. This finding suggests that components of the plant cell wall and of the animal extracellular matrix are synthesized by evolutionarily related enzymes even though the structures of the corresponding polysaccharides are entirely different from each other.
Structure type: oligomer
Location inside paper: Table 1
Trivial name: XXLG
Compound class: N-glycan, xyloglucan
Contained glycoepitopes: IEDB_114701,IEDB_136044,IEDB_137472,IEDB_141794,IEDB_142488,IEDB_146664,IEDB_190606,IEDB_983931,SB_165,SB_166,SB_187,SB_192,SB_195,SB_7,SB_88
Methods: ESI-MS, ESI-MS/MS, biological assays, genetic manipulations
Enzymes that release or process the structure: MUR3
Related record ID(s): 61085, 61086, 61088, 61089, 61090
NCBI Taxonomy refs (TaxIDs): 3702Reference(s) to other database(s): GTC:G18071YH, CCSD:
17576, CBank-STR:16692
Show glycosyltransferases
There is only one chemically distinct structure:
Found 
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