Cloning and expression of a Bacillus subtilis division initiation gene for which a homolog has not been identified in another organism

The Bacillus subtilis 168 division initiation genes defined by the temperature-sensitive mutations ts-1 and ts-12 were cloned into a 10.5-kilobase EcoRI fragment of DNA in the lambda EMBL4 vector. The two genes were separated by approximately 3 kilobases. The gene in which the ts-1 mutation resides was shown to be the same as the B. subtilis homolog of the Escherichia coli ftsZ gene. The other gene was named divIB. It showed no homology to any previously identified gene and coded for a protein of 30.1 kilodaltons which was probably membrane bound.