| There are approximately 50 genes involved with flagellar assembly and function in E.coli. To date, only 17 flagellum-related gene product assignments have been made. A number of questions remain concerning the relationship between certain flagellar gene products and chemotaxis or motility proteins, as well as concerning the regulation of flagellar assembly, and the regulation of flagellar gene transcription.;The flbB operon includes the flbB and flbB genes. The products of these genes are required for the transcription of all other flagellar, motility, and chemotaxis genes. The flbB operon was mapped on recombinant plasmids. Detailed localization of the flbB and flaI genes was accomplished by comparing the DNA sequence of various flbB operon deletion endpoints with complementation ability of the specific deletion clones. The DNA sequence of the flbB operon has been analyzed and is discussed. The flaI gene product has been overexpressed and identified as a 22 kilodalton protein.;The flaB operon, and flaN, and flaA genes were subcloned from a (lamda) fla transducing phage, and their physical map position determined. Three genes were found at the flaB locus; which have been designated flaBI, flaBII, and flaBIII. The cheY suppressor mutations which have previously been mapped to the flaB locus were further localized to flaBII. Reversed genetic methodology demonstrated that the null phenotype of the flaBII gene is Fla('-). The flaB operon gene products and flaA gene product were overexpressed by placing their transcription under the control of the lacUV5 or tac promoters. By correlating various DNA deletions and insertions DNA with the ability to complement specific flagellar mutants and code for polypeptides, the following gene product assignments were made: flaBI, 60 kilodaltons; flaBII, 38 kilodaltons; flaBIII, 28 kilodaltons; flaC, 56 kilodaltons; flaO, 16 kilodaltons; flaE, 54 kilodaltons; and flaA, 38 kilodaltons. Most of the flaB operon products as well as the flaA gene product have been preliminarily assigned to cytoplasmic, inner membrane, or outer membrane locations. The flaBII, flaBIII, and flaA gene products have been assigned to the inner membrane, the flaC gene product to the outer membrane, and the flaE gene product to the cytoplasm. |
