Department of Medical Laboratory Science and Biotechnology, Central Taiwan University of Science and Technology, Taichung, 406, Taiwan.
Curr Microbiol. 2020 Oct;77(10):2876-2885. doi: 10.1007/s00284-020-02093-1. Epub 2020 Jul 4.
The caseinolytic protease (Clp) system is essential for survival under stress conditions and for virulence in several pathogenic bacteria. Xanthomonas campestris pv. campestris (Xcc) is a plant pathogen which causes black rot disease in crucifers. In this study, the Xcc clpP gene which is annotated to encode the proteolytic core of Clp was characterized. Mutation of clpP resulted in susceptibility to high temperature and puromycin stresses. Site-directed mutagenesis revealed that S105, H130, and D179 are critical amino acid residues for ClpP function in puromycin tolerance. Inactivation of clpP also revealed an attenuation of virulence on the host plant and a reduction in the production of extracellular cellulase, mannanase, pectinase, and protease. The affected phenotypes of the clpP mutant could be complemented to wild-type levels by the intact clpP gene. Transcriptional analysis revealed that expression of clpP is induced under heat shock condition.
溶菌酶蛋白酶 (Clp) 系统对于在应激条件下的生存和几种致病性细菌的毒力至关重要。野油菜黄单胞菌 pv. 甘蓝型 (Xcc) 是一种植物病原体，可引起十字花科植物的黑腐病。在这项研究中，对 Xcc 的 clpP 基因进行了特征描述，该基因被注释为编码 Clp 的蛋白水解核心。clpP 的突变导致对高温和嘌呤霉素压力的敏感性。定点突变显示 S105、H130 和 D179 是 ClpP 在嘌呤霉素耐受性中的关键氨基酸残基。clpP 的失活还导致对宿主植物的毒力减弱，以及细胞外纤维素酶、甘露聚糖酶、果胶酶和蛋白酶的产生减少。clpP 突变体的受影响表型可以通过完整的 clpP 基因互补到野生型水平。转录分析显示，clpP 的表达在热休克条件下被诱导。
