A xylosyltransferase involved in the synthesis of a protein-associated xyloglucan in suspension-cultured dwarf-French-bean (Phaseolus vulgaris) cells and its interaction with a glucosyltransferase.
A particulate enzyme preparation made from suspension-cultured dwarf-French-bean (Phaseolus vulgaris) cv. Canadian Wonder cells was shown to incorporate xylose from UDP-D-[14C]xylose into polysaccharide. The reaction was dependent upon the presence of UDP-D-glucose and was stimulated, and apparently protected, by GDP-D-glucose and GDP-D-mannose, though neither was able to replace UDP-D-glucose as a glycosyl donor. The product of the reaction was identified as xyloglucan by analysis of products of enzyme breakdown and acid hydrolysis. Mr determination after proteinase K digestion indicated that the nascent xyloglucan is closely associated with protein. Preincubation of the enzyme with UDP-D-glucose stimulated incorporation from UDP-D-[14C]xylose, suggesting an 'imprecise' mechanism of biosynthesis, as defined by Waldron & Brett [(1985) in Biochemistry of Plant Cell Walls (Brett, C. T. & Hillman, J. R., eds.) (SEB Semin. Ser. 28), pp. 79-97, Cambridge University Press, Cambridge].
Campbell
R E
RE
Department of Botany, University of Glasgow, Scotland, U.K.
Brett
C T
CT
Hillman
J R
JR
D002413:Cations, Divalent / Q000494:pharmacology; D002850:Chromatography, Gel; D007887:Fabaceae / Q000187:drug effects / Q000201:enzymology; D005936:Glucans; D005964:Glucosyltransferases / Q000378:metabolism*; D006155:Guanosine Diphosphate Mannose / Q000494:pharmacology; D006156:Guanosine Diphosphate Sugars / Q000494:pharmacology; D010430:Pentosyltransferases / Q000378:metabolism*; D010946:Plants, Medicinal; D011134:Polysaccharides / Q000096:biosynthesis*; D011485:Protein Binding; D014532:Uridine Diphosphate Glucose / Q000494:pharmacology; D014540:Uridine Diphosphate Xylose / Q000494:pharmacology; D014990:Xylans; D000097608:UDP Xylose-Protein Xylosyltransferase
D002413:Cations, Divalent; D005936:Glucans; D005964:Glucosyltransferases; D006155:Guanosine Diphosphate Mannose; D006156:Guanosine Diphosphate Sugars; D010430:Pentosyltransferases; D011134:Polysaccharides; D014532:Uridine Diphosphate Glucose; D014540:Uridine Diphosphate Xylose; D014990:Xylans; D000097608:UDP Xylose-Protein Xylosyltransferase; C029353:xyloglucan; C100085:guanosine diphosphate glucose