Characterization of cheW genes of Leptospira interrogans and their effects in Escherichia coli.
The motility and chemotaxis systems are critical for the virulence of leptospires. In this study, the phylogenetic profiles method was used to predict the interaction of chemotaxis proteins. It was shown that CheW1 links to CheA1, CheY, CheB and CheW2; CheW3 links to CheA2, MCP (LA2426), CheB3 and CheD1; and CheW2 links only to CheW1. The similarity analysis demonstrated that CheW2 of Leptospira interrogans strain Lai had poor homology with CheW of Escherichia coli in the region of residues 30-50. In order to verify the function of these proteins, the putative cheW genes were cloned into pQE31 vector and expressed in wild-type E. coli strain RP437 or cheW defective strain RP4606. The swarming results indicated that CheW1 and CheW3 could restore swarming of RP4606 while CheW2 could not. Overexpression of CheW1 and CheW3 in RP437 inhibited the swarming of RP437, whereas the inhibitory effect of CheW2 was much lower. Therefore, we presumed that CheW1 and CheW3 might have the function of CheW while CheW2 does not. The existence of multiple copies of chemotaxis homologue genes suggested that L. interrogans strain Lai might have a more complex chemosensory pathway.
Department of Microbiology and Parasitology, Medicine School of Shanghai Jiaotong University, Shanghai 200025, China.
Zhen-Hong
ZH
Li
Ke
K
Dong
Jing-Chun
JC
Sun
Jian-Ping
JP
Yuan
Bao-Yu
BY
Hu
Jing-Xing
JX
Liu
Guo-Ping
GP
Zhao
Xiao-Kui
XK
Guo
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D002633:Chemotaxis / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics / Q000502:physiology*; D015870:Gene Expression; D006801:Humans; D007921:Leptospira interrogans / Q000235:genetics*; D008969:Molecular Sequence Data; D025941:Protein Interaction Mapping / Q000379:methods; D017386:Sequence Homology, Amino Acid; D019076:Transgenes / Q000502:physiology*
D001426:Bacterial Proteins; C051236:CheW protein, Bacteria