Open AccessFunction analysis of a bacterial tyrosine kinase, BtkB , in M yxococcus xanthus
Author(s) -
Kimura Yoshio,
Kato Takuya,
Mori Yumi
Publication year - 2012
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.1574-6968.2012.02651.x
Subject(s) - myxococcus xanthus , periplasmic space , mutant , biology , biochemistry , extracellular , wild type , kinase , tyrosine , cytoplasm , microbiology and biotechnology , gene , escherichia coli
M yxococcus xanthus BtkB is composed of an N ‐terminal periplasmic domain and a C ‐terminal cytoplasmic tyrosine kinase domain. The C ‐terminal cytoplasmic domain of BtkB was autophosphorylated in the presence of [γ‐ 32 P ] ATP and MgCl 2 , and the autophosphorylated BtkB was detected with antiphosphotyrosine antibody, suggesting that BtkB is a bacterial tyrosine ( BY ) kinase. BY kinases have been demonstrated in the production of extracellular polysaccharide ( EPS ), antibiotic resistance, stress response, and DNA metabolism. M yxococcus xanthus btkB gene was expressed mainly in the growth phase and early stages of fruiting body development. When cultured in nutrient medium at high temperature (37 °C), btkB mutant showed reduced maximum cell density as compared to the wild type. Under starvation conditions, btkB mutant cells formed fruiting bodies and spores about 24 h later than the wild‐type strain. The btkB mutant overproduced yellow pigment during development. Also, btkB mutant showed a decrease in EPS production when compared with the wild‐type strain. These results suggested that BtkB may play multiple roles in M . xanthus cells.