Taxonomic group: plant / Streptophyta
(Phylum: Streptophyta)
The structure was elucidated in this paperPublication DOI: 10.1111/j.1365-313X.2008.03724.xJournal NLM ID: 9207397Publisher: Oxford: Blackwell Scientific Publishers and BIOS Scientific Publishers for the Society for Experimental Biology
Correspondence: A.Marchant
soton.ac.uk
Institutions: Forestry and Forest Products Research Institute, Tsukuba, Ibaraki 305-8687, Japan, Department of Forest Genetics and Plant Physiology, SLU, SE-901 83 Umeå, Sweden, Centre National de la Recherche Scientifique FRE 3090, Institut Fédératif de Recherche Multidisciplinaire sur les Peptides 23, Université de Rouen, 76821 Mont Saint Aignan Cedex, France, National Agricultural Research Center, National Agriculture and Food Research Organisation, Tsukuba, Ibaraki, 305-8687, Japan, School of Biological Sciences, University of Southampton, Boldrewood Campus, Southampton, SO16 7PX, UK
Arabidopsis IRX10 and IRX10-LIKE (IRX10-L) proteins are closely related members of the GT47 glycosyltransferase family. Single gene knock-outs of IRX10 or IRX10-L result in plants with either a weak or no mutant phenotype. However irx10 irx10-L double mutants are severely affected in their development, with a reduced rosette size and infrequent formation of a small infertile inflorescence. Plants homozygous for irx10 and heterozygous for irx10-L have an intermediate phenotype exhibiting a short inflorescence compared with the wild type, and an almost complete loss of fertility. Stem sections of the irx10 homozygous irx10-L heterozygous or irx10 irx10-L double mutants show decreased secondary cell-wall formation. NMR analysis shows that signals derived from the reducing end structure of glucuronoxylan were detected in the irx10 single mutant, and in the irx10 homozygous irx10-L heterozygous combination, but that the degree of polymerization of the xylan backbone was reduced compared with the wild type. Additionally, xylans from irx10 stem tissues have an almost complete loss of the GlcUA side chain, whereas the level of 4-O-Me-GlcUA was similar to that in wild type. Deletion of the predicted signal peptide from the N terminus of IRX10 or IRX10-L results in an inability to rescue the irx10 irx10-L double mutant phenotype. These findings demonstrate that IRX10 and IRX10-L perform a critical function in the synthesis of glucuronoxylan during secondary cell-wall formation, and that this activity is associated with the formation of the xylan backbone structure. This contrasts with the proposed function of the tobacco NpGUT1, which is closely related to the Arabidopsis IRX10 and IRX10-L proteins, in rhamnogalacturonan II biosynthesis.
carbohydrates, cell wall, glycosyltransferase, Arabidopsis, hemicellulose
Structure type: oligomer ; 745
Location inside paper: Figure 8
Trivial name: X4G, X4U/X4G
Contained glycoepitopes: IEDB_114701,IEDB_115136,IEDB_140630,IEDB_167188,IEDB_174332
Methods: 1H NMR, GC-MS, ESI-MS, biological assays, genetic manipulations
Enzymes that release or process the structure: IRX10
Related record ID(s): 61084
NCBI Taxonomy refs (TaxIDs): 3702Reference(s) to other database(s): GTC:G65832ST
Show glycosyltransferases
There is only one chemically distinct structure:
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