Russell Jay H, Keiler Kenneth C
Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, United States of America.
PLoS One. 2008 Mar 12;3(3):e1756. doi: 10.1371/journal.pone.0001756.
Precise localization of individual proteins is required for processes such as motility, chemotaxis, cell-cycle progression, and cell division in bacteria, but the number of proteins that are localized in bacterial species is not known. A screen based on transposon mutagenesis and fluorescence activated cell sorting was devised to identify large numbers of localized proteins, and employed in Caulobacter crescentus. From a sample of the clones isolated in the screen, eleven proteins with no previously characterized localization in C. crescentus were identified, including six hypothetical proteins. The localized hypothetical proteins included one protein that was localized in a helix-like structure, and two proteins for which the localization changed as a function of the cell cycle, suggesting that complex three-dimensional patterns and cell cycle-dependent localization are likely to be common in bacteria. Other mutants produced localized fusion proteins even though the transposon has inserted near the 5' end of a gene, demonstrating that short peptides can contain sufficient information to localize bacterial proteins. The screen described here could be used in most bacterial species.
细菌的运动、趋化性、细胞周期进程和细胞分裂等过程需要单个蛋白质的精确定位，但细菌物种中定位蛋白质的数量尚不清楚。设计了一种基于转座子诱变和荧光激活细胞分选的筛选方法来鉴定大量定位蛋白质，并在新月柄杆菌中应用。从筛选中分离出的克隆样本中，鉴定出11种在新月柄杆菌中以前没有特征性定位的蛋白质，包括6种假定蛋白质。定位的假定蛋白质包括一种定位在螺旋状结构中的蛋白质，以及两种定位随细胞周期变化的蛋白质，这表明复杂的三维模式和细胞周期依赖性定位在细菌中可能很常见。其他突变体产生了定位融合蛋白，尽管转座子插入了基因的5'端附近，这表明短肽可以包含足够的信息来定位细菌蛋白质。这里描述的筛选方法可用于大多数细菌物种。
