Starch synthase (maltosyl-transferring) explained

Starch synthase (maltosyl-transferring)
Ec Number:	2.4.99.16

Starch synthase (maltosyl-transferring) (alpha1,4-glucan:maltose-1-P maltosyltransferase, GMPMT) is an enzyme with systematic name alpha-maltose 1-phosphate:(1->4)-alpha-D-glucan 4-alpha-D-maltosyltransferase.^[1] This enzyme catalyses the following chemical reaction

alpha-maltose 1-phosphate + [(1->4)-alpha-D-glucosyl]n

\rightleftharpoons phosphate + [(1->4)-alpha-D-glucosyl]n+2

The enzyme from the bacterium Mycobacterium smegmatis is specific for maltose.

Notes and References

1. Elbein AD, Pastuszak I, Tackett AJ, Wilson T, Pan YT . Last step in the conversion of trehalose to glycogen: a mycobacterial enzyme that transfers maltose from maltose 1-phosphate to glycogen . The Journal of Biological Chemistry . 285 . 13 . 9803–12 . March 2010 . 20118231 . 2843229 . 10.1074/jbc.M109.033944 . free .