Bobrov Alexander G, Kirillina Olga, Vadyvaloo Viveka, Koestler Benjamin J, Hinz Angela K, Mack Dietrich, Waters Christopher M, Perry Robert D
Department of Microbiology, Immunology, and Molecular Genetics, University of Kentucky, Lexington, KY, USA.
Environ Microbiol. 2015 Apr;17(4):947-59. doi: 10.1111/1462-2920.12419. Epub 2014 Mar 11.
The second messenger molecule cyclic diguanylate is essential for Yersinia pestis biofilm formation that is important for blockage-dependent plague transmission from fleas to mammals. Two diguanylate cyclases (DGCs) HmsT and Y3730 (HmsD) are responsible for biofilm formation in vitro and biofilm-dependent blockage in the oriental rat flea Xenopsylla cheopis respectively. Here, we have identified a tripartite signalling system encoded by the y3729-y3731 operon that is responsible for regulation of biofilm formation in different environments. We present genetic evidence that a putative inner membrane-anchored protein with a large periplasmic domain Y3729 (HmsC) inhibits HmsD DGC activity in vitro while an outer membrane Pal-like putative lipoprotein Y3731 (HmsE) counteracts HmsC to activate HmsD in the gut of X. cheopis. We propose that HmsE is a critical element in the transduction of environmental signal(s) required for HmsD-dependent biofilm formation.
第二信使分子环二鸟苷酸对于鼠疫耶尔森菌生物膜的形成至关重要，而生物膜的形成对于跳蚤依赖堵塞将鼠疫传播给哺乳动物具有重要意义。两种二鸟苷酸环化酶（DGCs）HmsT和Y3730（HmsD）分别负责体外生物膜的形成以及在印鼠客蚤肠道中生物膜依赖的堵塞。在此，我们鉴定出由y3729 - y3731操纵子编码的三方信号系统，该系统负责在不同环境中调节生物膜的形成。我们提供了遗传学证据，表明具有大的周质结构域的假定内膜锚定蛋白Y3729（HmsC）在体外抑制HmsD DGC活性，而外膜Pal样假定脂蛋白Y3731（HmsE）在印鼠客蚤肠道中抵消HmsC以激活HmsD。我们提出HmsE是HmsD依赖的生物膜形成所需环境信号转导中的关键元件。
