Study of the interactions between XpsG、H、J in Xanthomonas campestris pv. campestris

• Main Authors: Hsiang-Ling Lai, 賴祥玲
• Other Authors: Ling-Yun Chen
• Format: Others
• Language: zh-TW
• Published: 2002
• Online Access: http://ndltd.ncl.edu.tw/handle/90656758801768221508

碩士 === 中山醫學大學 === 生物化學研究所 === 90 === Xanthomonas campestris pv. campestris exports a number of hydrolytic enzymes to infect plants using type II secretion pathway. Type II secretion pathway is the main terminal branch of the general secretion pathway in gram-negative bacteria for extracellular secretion of toxins and hydrolytic enzymes. Extracellular secretion of proteins is regarded as a major virulence mechanism in bacteria infection. In order to resolve the problem of bacteria infection, the study of type II secretion pathway is important. The members of type II secretion pathway, XpsGHIJK, were assumed to form pilus-like structure and push secreted proteins through the outer membrane. In the past, the cross-linking experiment in P. aeruginosa revealed that GspG could interact with GspH,-I,-J, but the detail protein-protein interactions among GspG, -H, -I, -J is still unknown. In this study, analysis of the interactions between XpsG, -H, -J in Xanthomonas campestris pv. campestris by gel filtration and Ni-NTA affinity chromatography showed that : a. XpsH-his6 could interact with XpsG; b. XpsH-his6 could interact with XpsJ and change the fractionation of XpsJ in gel filtration chromatography ; c. XpsH could assist the formation of XpsG-XpsJ-his6 complex. These observations suggest that XpsH could regulate the complex formation of XpsG-XpsH-XpsJ.