THE GENE FIMU AFFECTS EXPRESSION OF SALMONELLA-TYPHIMURIUM TYPE-1 FIMBRIAE AND IS RELATED TO THE ESCHERICHIA-COLI TRANSFER-RNA GENE ARGU

The gene fimU, located on a recombinant plasmid carrying the Salmonell a typhimurium type 1 fimbrial gene cluster is closely related to the E scherichia coli tRNA gene argU. The fimU gene complements an E. coli a rgU mutant that is a P2 lysogen, thereby allowing the phage P4 to grow in this strain but preventing the growth of phage lambda. In addition , fimU was shown to be involved in fimbrial expression since transform ants of the E. coli argU mutant could produce fimbriae only in the pre sence of fimU but not in its absence, whereas in an E. coli argU(+) st rain fimbriation did not require the fimU gene.