Open AccessIdentification of the Mesorhizobium loti gene responsible for glycerophosphorylation of periplasmic cyclic β‐1,2‐glucans
Author(s) -
Kawaharada Yasuyuki,
Kiyota Hiromasa,
Eda Shima,
Minamisawa Kiwamu,
Mitsui Hisayuki
Publication year - 2010
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/j.1574-6968.2009.01843.x
Subject(s) - periplasmic space , mesorhizobium , rhizobia , mutant , gene , wild type , biochemistry , chemistry , biology , phenotype , symbiosis , mutation , microbiology and biotechnology , genetics , bacteria , escherichia coli
Periplasmic cyclic β‐1,2‐glucans play a crucial role in symbiosis as well as in hypo‐osmotic adaptation for rhizobia. These glucans are modified in many species by anionic substituents such as glycerophosphoryl and succinyl ones, but their role remains to be examined. In this work, the cgmA homolog is shown to be responsible for glycerophosphorylation of cyclic β‐1,2‐glucans in Mesorhizobium loti . The mutation in cgmA converted most anionic glucans into neutral ones, leaving a small amount of succinylated ones. An additional mutation in opgC , which encodes a succinyltransferase homolog, abolished the residual succinyl substituents in the cgmA ‐mutant background. The double mutant in cgmA and opgC did not show any significant phenotypic differences from the wild type during both vegetative growth and symbiosis. It is concluded that the anionic substituents make a minor contribution, if any, to the effectiveness of cyclic β‐1,2‐glucans in M. loti .