The divIVA minicell locus of Bacillus subtilis.
The Bacillus subtilis divIVA1 mutation causes misplacement of the septum during cell division, resulting in the formation of small, circular, anucleate minicells. This study reports the cloning and sequence analysis of 2.4 kb of the B. subtilis chromosome including the divIVA locus. Three open reading frames were identified: orf, whose function is unknown; divIVA; and isoleucyl tRNA synthetase (ileS). We identified the point mutation in the divIVA1 mutant allele. Inactivation of divIVA produces a minicell phenotype, whereas overproduction of DivIVA results in a filamentation phenotype. Mutants with mutations at both of the minicell loci of B. subtilis, divIVA and divIVB, possess a minicell phenotype identical to that of the DivIVB- mutant. The DivIVA-mutants, but not the DivIVB- mutants, show a decrease in sporulation efficiency and a delay in the kinetics of endospore formation. The data support a model in which divIVA encodes the topological specificity subunit of the minCD system. The model suggests that DivIVA acts as a pilot protein, directing minCD to the polar septation sites. DivIVA also appears to be the interface between a sporulation component and MinCD, freeing up the polar septation sites for use during the asymmetric septation event of the sporulation process.
Cha
J H
JH
Department of Microbiology and Immunology, University of South Carolina School of Medicine, Columbia, USA.
Stewart
G C
GC
D000483:Alleles; D000595:Amino Acid Sequence; D001412:Bacillus subtilis / Q000166:cytology* / Q000235:genetics* / Q000502:physiology; D001426:Bacterial Proteins; D001483:Base Sequence; D018797:Cell Cycle Proteins / Q000737:chemistry / Q000235:genetics* / Q000502:physiology*; D002455:Cell Division / Q000235:genetics; D016386:Chromosome Walking; D003001:Cloning, Molecular; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D010641:Phenotype; D010957:Plasmids; D017354:Point Mutation; D015183:Restriction Mapping; D013171:Spores, Bacterial / Q000502:physiology; D014169:Transformation, Bacterial
D001426:Bacterial Proteins; D018797:Cell Cycle Proteins; C104636:DivIVA protein, bacteria