The interaction of xylosyltransferase and glucuronyltransferase involved in glucuronoxylan synthesis in pea (Pisum sativum) epicotyls.
A particulate enzyme preparation from etiolated pea (Pisum sativum) epicotyls was found to incorporate xylose from UDP-D-xylose into beta-(1----4)-xylan. The ability of this xylan to act as an acceptor for incorporation of [14C]glucuronic acid from UDP-D-[14C]glucuronic acid in a subsequent incubation was very limited, even though glucuronic acid incorporation was greatly prolonged when UDP-D-xylose was present in the same incubation as UDP-D-[14C]glucuronic acid. This indicated that glucuronic acid could not be added to preformed xylan. However, the presence of UDP-D-glucuronic acid inhibited incorporation of [14C]xylose from UDP-D-[14C]xylose into beta-(1----4)-xylan, and neither S-adenosylmethionine nor acetyl-CoA stimulated either the xylosyltransferase or the glucuronyltransferase.
Baydoun
E A
EA
Department of Biology, American University of Beirut, Lebanon.
Waldron
K W
KW
Brett
C T
CT
D000105:Acetyl Coenzyme A / Q000494:pharmacology; D005965:Glucuronates / Q000378:metabolism; D020723:Glucuronic Acid; D014453:Glucuronosyltransferase / Q000378:metabolism*; D010430:Pentosyltransferases / Q000378:metabolism*; D010944:Plants / Q000201:enzymology / Q000378:metabolism*; D011134:Polysaccharides / Q000096:biosynthesis*; D012436:S-Adenosylmethionine / Q000494:pharmacology; D014990:Xylans / Q000096:biosynthesis*; D014994:Xylose / Q000378:metabolism; D000097608:UDP Xylose-Protein Xylosyltransferase
D000105:Acetyl Coenzyme A; D005965:Glucuronates; D020723:Glucuronic Acid; D014453:Glucuronosyltransferase; D010430:Pentosyltransferases; D011134:Polysaccharides; D012436:S-Adenosylmethionine; D014990:Xylans; D014994:Xylose; D000097608:UDP Xylose-Protein Xylosyltransferase; C038910:glucuronoxylan