The Bacillus subtilis chromosome

Previous observations concerning the ability of the spore-converting bacteriophage PMB12 to cause sporulation in certain sporulation-deficient mutants of Bacillus subtilis 168 were extended to include a spoOK mutant and a mutant temperature sensitive for sporulation due to a ribosomal mutation. Mutants of PMB12 that were unable to induce sporulation in the spoOK mutant were isolated to determine whether PMB12-encoded products had to affect the sporulation-specific functions of both the transcription and the translation systems of B. subtilis to induce sporulation. A complementation assay for spore conversion was used to assign the spore conversion-negative PMB12 mutants to four groups. One group of mutants repressed the ability of wild-type PMB12 to induce sporulation. None of the spore conversion-negative PMB12 mutants could induce significant levels of sporulation in B. subtilis mutants that were temperature sensitive for sporulation due to mutations in the beta subunit of ribonucleic acid polymerase or the 30S ribosomal subunit. Our data suggest that PMB12 may have at least three genes for spore conversion. The products of these genes apparently interact with a host cell pathway that is expressed during the earliest stage of sporulation and is not dependent for expression upon sporulation-specific functions of the host cell's transcription and translation systems.

Section: Resultsmentioning

confidence: 98%

Analysis of Bacillus subtilis sporulation with spore-converting bacteriophage PMB12

Kinney¹,

Bramucci²

1981

“…Genetic mapping of Isolated mutations. All previously isolated B. subtilis mutants which lack in vitro SDH enzyme activity carry mutations in the sdh region, formerly designated citF (see above), at 255°on the chromosomal map (13,19). The respective mutations in the 21 newly isolated mutants were all linked to ilvCI by transformation (data not shown), and they were thus assumed to be located in the sdh region of the chromosome.…”

Section: Spizizen This Laboratorymentioning

confidence: 99%

Reconstitution of succinate dehydrogenase in Bacillus subtilis by protoplast fusion

Hederstedt¹,

Magnusson²,

Rutberg³

1982

Bacillus subtilis succinate dehydrogenase (SDH) is composed of two unequal subunits designated Fp (Mr, 65,000) and Ip (Mr. 28,000). The enzyme is structurally and functionally complexed to cytochrome b 558 (Mr, 19,000) in the membrane. A total of 21 B. subtilis SDH-negative mutants were isolated. The mutants fall into five phenotypic classes with respect to the presence and localization of the subunits of the SDH-cytochrome b558 complex. One class contains mutants with an inactive membrane-bound complex. Membrane-bound enzymatically active SDH could be reconstituted in fused protoplasts of selected pairs of SDH-negative mutants. Most likely reconstitution is due to the assembly of preformed subunits in the fused cells. On the basis of the reconstitution data, the mutants tested could be divided into three complementation groups. The combined data of the present and previous work indicate that the complementation groups correspond to the structural genes for the three subunits of the membrane-bound SDH-cytochrome b558 complex. A total of 31 SDH-negative mutants of B. subtilis have now been characterized. The respective mutations all map in the citF locus at 255 degrees on the B. subtilis chromosomal map. In the present paper, we have revised the nomenclature for the genetics of SDH in B. subtilis. All mutations which give an SDH-negative phenotype will be called sdh followed by an isolation number. The designation citF will be omitted, and the citF locus will be divided into three genes: sdhA, sdhB, and sdhC. Mutations in sdhA affect cytochrome b558, mutations in sdhB affect Fp, and mutations in sdhC affect Ip.

“…By genetic studies of many sporulation mutants ofBacillus subtilis that are blocked at stage 0, nine stage 0 loci have been identified (5,7,8,17,18,20). Among them, spoOA mutations are the most pleiotropic for many properties associated with sporulation, such as competence for genetic transformation, sensitivity to bacteriophage +2, and the production of antibiotics (7,17,20).…”

mentioning

confidence: 99%

“…On the other hand, Trowsdale et al (22) reported that spoOA mutations were recessive when spoOAlspoOA+ merodiploids had abr mutations. As shown in Table 1, the fragment does not contain spoIIIA, spolIIB, or spoIVB genes, which map near the locus of the spoOC and spoOA genes (5).…”

mentioning

confidence: 99%

Cloning of sporulation genes spo0A and spo0C of Bacillus subtilis onto rho 11 temperate bacteriophage

Ikeuchi¹,

Kudoh²,

Kurahashi³

1983

A HindIII fragment harboring the intact spo0C gene of Bacillus subtilis was cloned with rho 11 temperate bacteriophage as a vector. Transformation experiments with the DNA from rho 11 dspo0C+ specialized transducing phage showed that the spo0C gene resides on a 5.3-megadalton fragment generated by HindIII digestion. The 5.3-megadalton fragment also contains the intact spo0A gene, but not spoIIIA, spoIIIB, or spoIVB.