SEQUENCE ANALYSIS OF THE BACTERIAL FLAGELLAR MOTOR

这项建议是针对生物学的理解 能量传递、转换、结构和过程 装配，如细菌鞭毛马达的例子。狂野的- 编码成分的选定基因的类型和突变等位基因 鼠伤寒沙门氏菌鞭毛马达 将进行排序，以确定 蛋白质，以及这些区域内的哪些氨基酸是最 对装配和功能的各个方面至关重要；提案 建立在大量现有的详细经典基因的基础上 信息。主要有三个主题：(一)分析五个 已知的基因(flAII.2、flQ、flan、mota和motb) 参与能量转换(质子势能的转换 变成旋转的机械功)和切换(在 逆时针和顺时针旋转)；(2)比较 鞭毛蛋白、挂钩蛋白和挂钩相关的结构基因 蛋白质，试图发现它们识别的基础 通过鞭毛特定的输出途径，而不是通过 常规N末端信号肽依赖途径；(Iii) 鞭毛蛋白基因突变等位基因的分析 装配失败或装配成异常螺旋 多晶型，以期识别重要的残基 在生成的准等效亚单位间相互作用中 细丝的螺旋度。随着假说的出现， 突变序列分析，它们将通过产生位点- 定向突变。

The proposal is directed to an understanding of biological processes of energy transduction, switching, structure, and assembly, as exemplified in the bacterial flagellar motor. Wild- type and mutant alleles of selected genes coding for components of the flagellar motor of the bacterium Salmonella typhimurium will be sequenced with a view to determining which regions of the proteins, and which amino acids within those regions, are most critical for various aspects of assembly and function; the proposal builds on a large existing body of detailed classical genetic information. There are three main topics: (i) analysis of the five genes (flaAII.2, flaQ, flaN, motA, and motB) that are known to be involved in energy transduction (conversion of proton potential into mechanical work of rotation) and switching (between counterclockwise and clockwise rotation); (ii) comparison of the structural genes for flagellin, hook protein, and hook-associated proteins in an attempt to discover the basis for their recognition by a flagellar-specific export pathway rather than by the conventional N-terminal signal peptide dependent pathway; (iii) analysis of mutant alleles in the flagellin gene that give rise to failure of assembly or to assembly into abnormal helical polymorphs, with a view to identifying residues that are important in the quasi-equivalent inter-subunit interactions that generate the helicity of the filament. As hypotheses emerge from the mutant sequence analysis, they will be tested by generating site- directed mutations.