Institut Pasteur, Unité de Génétique des Biofilms, 28 rue du Dr. Roux, 75724, Paris, CEDEX 15, France.
Departamento de Biología Celular, Genética y Fisiología, Facultad de Ciencias. Universidad de Málaga, Málaga, Spain.
Sci Rep. 2017 Sep 12;7(1):11326. doi: 10.1038/s41598-017-10902-0.
Escherichia coli is a commensal or pathogenic bacterium that can survive in diverse environments. Adhesion to surfaces is essential for E. coli colonization, and thus it is important to understand the molecular mechanisms that promote this process in different niches. Autotransporter proteins are a class of cell-surface factor used by E. coli for adherence. Here we characterized the regulation and function of YeeJ, a poorly studied but widespread representative from an emerging class of autotransporter proteins, the inverse autotransporters (IAT). We showed that the yeeJ gene is present in ~40% of 96 completely sequenced E. coli genomes and that YeeJ exists as two length variants, albeit with no detectable functional differences. We demonstrated that YeeJ promotes biofilm formation in different settings through exposition at the cell-surface. We also showed that YeeJ contains a LysM domain that interacts with peptidoglycan and thus assists its localization into the outer membrane. Additionally, we identified the Polynucleotide Phosphorylase PNPase as a repressor of yeeJ transcription. Overall, our work provides new insight into YeeJ as a member of the recently defined IAT class, and contributes to our understanding of how commensal and pathogenic E. coli colonise their environments.
大肠杆菌是一种共生或致病细菌，可以在各种环境中生存。粘附在表面对于大肠杆菌的定植至关重要，因此了解促进不同生态位中这一过程的分子机制非常重要。自转运蛋白是大肠杆菌用于粘附的一类细胞表面因子。在这里，我们对 YeeJ 进行了表征，YeeJ 是一种研究较少但广泛存在的新兴自转运蛋白（反向自转运蛋白，IAT）类别的代表。我们表明，yeeJ 基因存在于~40%的 96 个完全测序的大肠杆菌基因组中，并且 YeeJ 存在两种长度变体，尽管没有检测到明显的功能差异。我们证明 YeeJ 通过在细胞表面暴露来促进不同环境中的生物膜形成。我们还表明，YeeJ 含有一个 LysM 结构域，该结构域与肽聚糖相互作用，从而有助于其定位到外膜中。此外，我们确定多核苷酸磷酸化酶 PNPase 是 yeeJ 转录的抑制剂。总的来说，我们的工作为 YeeJ 作为最近定义的 IAT 类别的成员提供了新的见解，并有助于我们理解共生和致病性大肠杆菌如何定植其环境。
