Title Molecular Analysis of the Copper-Responsive CopRSCD of a Pathogenic Pseudomonas fluorescens Strain
Author Yong-hua Hu1,2, Hua-lei Wang3, Min Zhang1,2, and Li Sun1*
Address 1Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, P. R. China, 2Graduate University of the Chinese Academy of Sciences, Beijing 100049, P. R. China, 3Hang Zhou EnzySource Biotechnology Co., Ltd., Hangzhou 310030, P. R. China
Bibliography Journal of Microbiology, 47(3),277-286, 2009,
Key Words CopABCD, copper resistance, CopR, Pseudomonas fluorescens, virulence
Abstract CopRS/CopABCD is one of the known systems that control copper homeostasis in bacteria. Although CopRS/CopABCD homologues are found to exist in Pseudomonas fluorescens, the potential role of this system in P. fluorescens has not been investigated. In this study a genetic cluster, consisting of copR, S, C, and D but lacking copAB, was identified in a pathogenic P. fluorescens strain (TSS) isolated from diseased fish. The copRSCD cluster was demonstrated to be required for full copper resistance and regulated at the transcription level by Cu. Expression of copCD is regulated directly by the two-component response regulator CopR, which also regulates its own expression. Interruption of the regulated expression of copR affected bacterial growth, biofilm formation, and tissue dissemination and survival. A mutant CopR, which lacks the N-terminal signal receiver domain and is constitutively active, was found to have an attenuating effect on bacterial virulence when expressed in TSS. To our knowledge, this is the first report that suggests a link between CopR and bacterial pathogenicity in P. fluorescens.