Structural genes for flagellar hook-associated proteins in Salmonella typhimurium

Abstract

The flaW, flaU and flaV genes of S. typhimurium LT2 were cloned into pBR322. These genes were mapped on the cloned DNA fragments by restriction endonuclease analysis and construction of the deletion derivatives. Their gene products were identified, by the minicell method, as proteins whose MW were estimated to be 59,000 for the flaW product, 31,000 for the flaU product and 48,000 for the flaV product. These values are identical to those of 3 spp. of hook-associated proteins (HAP), namely, HAP1, HAP3 and HAP2. Antibodies against HAP1, HAP3, and HAP2 specifically reacted with the gene products of flaW, flaU and flaV, respectively. Therefore, they are structurally genes for HAP. The antibodies against HAP 1 and HAP3 also specifically reacted with the gene products of flaS anf flaT of Escherichia coli, respectively. This indicates that these gene products are HAP in E. coli. This result is consistent with the demonstration that flaS and flaT of E. coli are functionally homologous with flaW and flaU of S. typhimurium.