期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2005
卷号：102
期号：31
页码：11082-11087
DOI：10.1073/pnas.0502663102
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：The cupA gene cluster of Pseudomonas aeruginosa encodes components of a putative fimbrial structure that enable this opportunistic human pathogen to form biofilms on abiotic surfaces. In P. aeruginosa, cupA gene expression is repressed by MvaT, a putative transcription regulator thought to belong to the H-NS family of nucleoid-associated proteins that typically function by repressing transcription. Here, we present evidence that MvaT controls phase-variable (ON/OFF) expression of the cupA fimbrial gene cluster. Using a directed proteomic approach, we show that MvaT associates with a related protein in P. aeruginosa called MvaU. Analysis with a bacterial two-hybrid system designed to facilitate the study of protein dimerization indicates that MvaT and MvaU can form both heteromeric and homomeric complexes, and that formation of these complexes is mediated through the N-terminal regions of MvaT and MvaU, both of which are predicted to adopt a coiled-coil conformation. We show further that, like MvaT, MvaU can repress phase-variable expression of the cupA gene cluster. Our findings suggest that fimbrial genes important for biofilm formation can be expressed in a phase-variable manner in P. aeruginosa, provide insight into the molecular mechanism of MvaT-dependent gene control, and lend further weight to the postulate that MvaT proteins are H-NS-like in nature.
