Open AccessBifunctional sucrose phosphate synthase/phosphatase is involved in the sucrose biosynthesis by M ethylobacillus flagellatus KT
Author(s) -
But Sergey Y.,
Khmelenina Valenti.,
Reshetnikov Alexander S.,
Trotsenko Yuri A.
Publication year - 2013
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/1574-6968.12219
Subject(s) - biochemistry , biology , sucrose , phosphofructokinase 2 , sucrose phosphate synthase , fructose , escherichia coli , sucrose synthase , enzyme , microbiology and biotechnology , gene , invertase
The aerobic obligate methylotroph M ethylobacillus flagellatus KT was shown to synthesize sucrose in the presence of 0.5–2% NaCl in the growth medium. In the genome of this bacterium, an open reading frame ( ORF ) encoding a predicted 84‐kD polypeptide homologous to the plant and cyanobacterial sucrose phosphate synthases ( SPS s) was found. Using heterologous expression of the putative sps gene in E scherichia coli, followed by affinity chromatography, pure recombinant protein SPS ‐ H is 6 was obtained. The enzyme catalyzed two reactions: conversion of fructose 6‐phosphate and UDP ‐glucose into sucrose 6‐phosphate and hydrolysis of sucrose 6‐phosphate to sucrose. The bifunctional sucrose phosphate synthase/phosphatase ( SPS / SPP ) was a 340 kDa homotetrameric Mg 2+ ‐dependent enzyme activated by fructose 1,6‐phosphate 2 and ATP but inhibited by glucose 6‐phosphate, fructose 1‐phosphate, AMP and inorganic phosphate. The amino acid sequence of the protein had a C ‐terminal domain homologous to SPP s. This correlated with the absence of the spp gene in the M . flagellatus chromosome. The ORF s homologous to the M . flagellatus SPS were found in the genomes of another obligate methylotroph M ethylovorus glucosetrophus as well as the lithoautotrophic bacteria A cidithiobacillus ferrooxidans , N itrosomonas europaea and N itrosospira multiformis whose genomes lacked the spp genes. Thus, data extending the knowledge of biochemical properties of bacterial SPS s have been obtained.