The smoB mutation suppressing cell filamentation and ability to support the multiplication of phage P22 in Salmonella typhimurium.

Isolation and properties of a Salmonella typhimurium mutant smoB are described. The mutation maps at unit 99 of the S. typhimurium chromosome between pyrB and deoC. It suppresses cell filamentation and temperature sensitivity of histidine-constitutive mutants, but does not restore the normal regulatory pattern to the histidine operon. Strains carrying the mutation have greatly reduced ability to support the growth of phage P22, but not of ES18 or Felix O.