Reaction: α-D-galactosyl-(1→3)-1D-myo-inositol + sucrose = myo-inositol + raffinose
For diagram of reaction click here.
Glossary: raffinose = β-D-fructofuranosyl α-D-galactopyranosyl-(1→6)-α-D-glucopyranoside
Other name(s): 1-α-D-galactosyl-myo-inositol:sucrose 6-α-D-galactosyltransferase; α-D-galactosyl-(1→3)-myo-inositol:sucrose 6-α-D-galactosyltransferase; raffinose synthase; RafS
Systematic name: α-D-galactosyl-(1→3)-1D-myo-inositol:sucrose 6-α-D-galactosyltransferase
Comments: 4-Nitrophenyl α-D-galactopyranoside can also act as donor. The enzyme also catalyses an exchange reaction between raffinose and sucrose (cf. EC 184.108.40.206, inositol 3-α-galactosyltransferase).
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 62213-45-0
1. Lehle, L. and Tanner, W. The function of myo-inositol in the biosynthesis of raffinose. Purification and characterization of galactinol:sucrose 6-galactosyltransferase from Vicia faba seeds. Eur. J. Biochem. 38 (1973) 103-110. [PMID: 4774118]
2. Lehle, L., Tanner, W. and Kandler, O. Myo-inositol, a cofactor in the biosynthesis of raffinose. Hoppe-Seyler's Z. Physiol. Chem. 351 (1970) 1494-1498. [PMID: 5491608]