State Key Laboratory of Agrobiotechnology and College of Biological Sciences, China Agricultural University, Beijing, PR China.
Microbiol Res. 2011 Dec 20;166(8):606-17. doi: 10.1016/j.micres.2010.12.001. Epub 2011 Jan 13.
We here report the sequence and functional analysis of cstB of Azospirillum brasilense Sp7. The predicted cstB contains C-terminal two PAS domains and N-terminal part which has similarity with CheB-CheR fusion protein. cstB mutants had reduced swarming ability compared to that of A. brasilense wild-type strain, implying that cstB was involved in chemotaxis in A. brasilense. A microscopic analysis revealed that cstB mutants developed mature cyst cells more quickly than wild type, indicating that cstB is involved in cyst formation. cstB mutants were affected in colony morphology and the production of exopolysaccharides (EPS) which are essential for A. brasilense cells to differentiate into cyst-like forms. These observations suggested that cstB was a multi-effector involved in cyst development and chemotaxis in A. brasilense.
我们在此报告巴西固氮螺菌 Sp7 的 cstB 的序列和功能分析。预测的 cstB 包含 C 末端的两个 PAS 结构域和与 CheB-CheR 融合蛋白具有相似性的 N 末端部分。与巴西固氮螺菌野生型菌株相比，cstB 突变体的游动能力降低，这表明 cstB 参与了巴西固氮螺菌的趋化作用。显微镜分析表明，cstB 突变体比野生型更快地发育成熟的胞囊细胞，表明 cstB 参与了胞囊的形成。cstB 突变体在菌落形态和胞外多糖 (EPS) 的产生方面受到影响，EPS 对巴西固氮螺菌细胞分化为类似胞囊的形式是必不可少的。这些观察结果表明，cstB 是一个多效因子，参与巴西固氮螺菌的胞囊发育和趋化作用。
