NDP-glucose—starch glucosyltransferase explained

NDP-glucose-starch glucosyltransferase
Ec Number:	2.4.1.242

In enzymology, a NDP-glucose—starch glucosyltransferase is an enzyme that catalyzes the chemical reaction

NDP-glucose + (1,4-alpha-D-glucosyl)n

\rightleftharpoons NDP + (1,4-alpha-D-glucosyl)n⁺1

Thus, the two substrates of this enzyme are NDP-glucose and (1,4-alpha-D-glucosyl)n, whereas its two products are NDP and (1,4-alpha-D-glucosyl)n+1.

This enzyme belongs to the family of glycosyltransferases, specifically the hexosyltransferases. The systematic name of this enzyme class is NDP-glucose:1,4-alpha-D-glucan 4-alpha-D-glucosyltransferase. Other names in common use include granule-bound starch synthase, starch synthase II (ambiguous), waxy protein, starch granule-bound nucleoside diphosphate glucose-starch, glucosyltransferase, granule-bound starch synthase I, GBSSI, granule-bound starch synthase II, GBSSII, GBSS, and NDPglucose-starch glucosyltransferase.

References

• Tsai CY . 1974 . The function of the waxy locus in starch synthesis in maize endosperm . Biochem. Genet. . 11 . 83 - 96 . 4824506 . 10.1007/BF00485766 . 2 . 23024343 .
• Nakamura T, Vrinten P, Hayakawa K, Ikeda J . 1998 . Characterization of a granule-bound starch synthase isoform found in the pericarp of wheat . Plant Physiol. . 118 . 451 - 9 . 9765530 . 10.1104/pp.118.2.451 . 2 . 34820 .
• Fujita N, Taira T . 1998 . A 56-kDa protein is a novel granule-bound starch synthase existing in the pericarps, aleurone layers, and embryos of immature seed in diploid wheat (Triticum monococcum L.) . Planta . 207 . 125 - 32 . 9951718 . 10.1007/s004250050464 . 1 . 7146307 .
• Murai J, Taira T, Ohta D . 1999 . Isolation and characterization of the three Waxy genes encoding the granule-bound starch synthase in hexaploid wheat . Gene . 234 . 71 - 9 . 10393240 . 10.1016/S0378-1119(99)00178-X . 1 .
• Nelson OE . 1968 . The waxy locus in maize. II The location of the controlling element alleles . Genetics . 60 . 507 - 524 . 17248421 . 3 . 10.1093/genetics/60.3.507 . 1212058.