Reaction: phosphoenolpyruvate + [β-D-GlcA-(1→4)-2-O-Ac-β-D-GlcA-(1→4)-β-D-Glc-(1→4)-[3-O-(CH3CH(OH)CH2C(O))-4,6-CH3(COO–)C-β-D-Gal-(1→4)-β-D-Glc-(1→4)-β-D-Glc-(1→4)-β-D-Glc-(1→6)]-2(or 3)-O-Ac-α-D-Glc-(1→6)]n = [β-D-GlcA-(1→4)-2-O-Ac-β-D-GlcA-(1→4)-β-D-Glc-(1→4)-[3-O-(CH3CH(OH)CH2C(O))-4,6-CH3(COO–)C-β-D-Gal-(1→3)-4,6-CH3(COO–)C-β-D-Glc-(1→4)-β-D-Glc-(1→4)-β-D-Glc-(1→6)]-2(or 3)-O-Ac-α-D-Glc-(1→6)]n + phosphate
Other name(s): PssM; phosphoenolpyruvate:[D-GlcA-β-(1→4)-2-O-Ac-D-GlcA-β-(1→4)-D-Glc-β-(1→4)-[3-O-CH3-CH2CH(OH)C(O)-D-Gal-β-(1→4)-D-Glc-β-(1→4)-D-Glc-β-(1→4)-D-Glc-β-(1→6)]-2(or 3)-O-Ac-D-Glc-α-(1→6)]n 4,6-O-(1-carboxyethan-1,1-diyl)transferase
Systematic name: phosphoenolpyruvate:[β-D-GlcA-(1→4)-2-O-Ac-β-D-GlcA-(1→4)-β-D-Glc-(1→4)-[3-O-CH3-CH2CH(OH)C(O)-4,6-CH3(COO–)C-β-D-Gal-(1→4)-β-D-Glc-(1→4)-β-D-Glc-(1→4)-β-D-Glc-(1→6)]-2(or 3)-O-Ac-α-D-Glc-(1→6)]n 4,6-O-(1-carboxyethan-1,1-diyl)transferase
Comments: The enzyme is responsible for pyruvylation of the subterminal glucose in the acidic octasaccharide repeating unit of the exopolysaccharide of Rhizobium leguminosarum (bv. viciae strain VF39) which is necessary to establish nitrogen-fixing symbiosis with Pisum sativum, Vicia faba, and Vicia sativa.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
References:
1. Ivashina, T.V., Fedorova, E.E., Ashina, N.P., Kalinchuk, N.A., Druzhinina, T.N., Shashkov, A.S., Shibaev, V.N. and Ksenzenko, V.N. Mutation in the pssM gene encoding ketal pyruvate transferase leads to disruption of Rhizobium leguminosarum bv. viciae—Pisum sativum symbiosis. J. Appl. Microbiol. 109 (2010) 731-742. [PMID: 20233262]