Abstract

Honglei Ding, Tao Liu, Linping Huang, Weijun Zhang, Ping Luo, Qinghua Xie, Zhen Liu, Gang Guo, Xuhu Mao* and Quanming Zou

Helicobacter pylori infect nearly half of the world’s population and are associated with a spectrum of gastric maladies. The cytotoxin-associated gene pathogenicity island (cag PAI) encoding a type IV secretion system (T4SS) has been implicated in a series of host responses during infection. The cag PAI contains about 28 - 30 open-reading frames, for most of which the exact function is not well characterized or totally unknown and a delivered effector, CagA that becomes tyrosine phosphorylated upon delivery into host cells and initiates the changes in cell signaling. Here, we cloned one such cag PAI protein, CagM, which is encoded by the gene HP0537 from H. pylori strain 26695 and expressed the gene in Escherichia coli M15. 6xHis-tagged CagM protein was purified with one-step Ni-NTA affinity column chromatography. The IgG antibody against CagM was produced by immuning rabbit and purified by protein A sepharose chromatography, finally, we showed that CagM protein localized to the bacterial inner and outer membrane and the conclusion was consistent to some bioinformatics result.