Morphology and patterns of protein synthesis during sporulation of Bacillus subtilis Eryr spo(Ts) mutants

Transcriptional control of synthesis of acid-soluble proteins in sporulating Bacillus subtilis

The major acid-soluble spore proteins (ASSPs) isolated from mature spores of Bacillus subtilis are designated alpha, beta, and gamma (about 60, 60, and 100 amino acids in length, respectively). Alpha and beta are very similar, and gamma is very similar to a less predominant ASSP called delta (about 115 amino acids). A minor and very basic ASSP called epsilon is the same size as alpha and beta but is unrelated antigenically. These and several minor ASSPs comprise at least three related families of sporulation-specific gene products. Expression of the alpha and beta genes, detectable as functional mRNA in vitro, coincides with the time of synthesis of all of the major ASSPs in vivo. This apparently coordinate expression is dependent on at least the spo0A, spoIIA, and spoIIIA loci, but not on the spoIVA or spoVA loci, consistent with the late stage of this expression (initiating at 3.5 h after the start of sporulation and peaking at 5 h after start of sporulation). A few minor ASSPs may be asynchronously expressed.

Genetic heterogeneity in the cysA-fus region of the Bacillus subtilis chromosome: identification of the hos gene

We identified a new gene, hos, which exerts different sporulation phenotypes in Bacillus subtilis strains with different genetic backgrounds. The hos+ gene showed normal sporulation in the genetic background of JH642 but showed temperature-sensitive sporulation in that of the Tano-oka W. The hos gene was mapped between cysA and rpoB.

Revertants of a streptomycin-resistant, oligosporogenous mutant of Bacillus subtilis

Revertants of a streptomycin-resistant (Strr), oligosporogenous (Spo-) mutant of Bacillus subtilis were selected form the ability to sporulate. The revertants obtained fell into two phenotypic classes: Strs Spo+ (streptomycin-sensitive, sporeforming), which arose by reversion of the streptomycin resistance mutations of the parent strain; and Strr Spo+, which arose by the acquisition of additional mutations, some of which were shown to affect ribosomal proteins. Alterations of ribosomal proteins S4 and S16 in the 30S subunit and L18 inthe 50S subunit were detected in Strr Spo+ revertants by polyacrylamide gel electrophoresis. Streptomycin resistance of the parental strain and the Strr revertants was demonstrated to reside in the 30S ribosomal subunit. The second site mutations of the revertants depressed the level of streptomycin resistance in vivo and in the in vitro translation of phage SP01 messenger ribonucleic acid (mRNA) relative to the resistance exhibited by the Strr parental strain. The Strr parent grew slowly and sporulated at approximately 1% of the wild type level. The Strr revertants closely resembled the wild type strain with regard to growth and sporulation. The Strr revertants grew at rates intermediate between those of the Strr patent and wild type, and sporulated at wild type levels.

Acid-soluble spore proteins of Bacillus subtilis

Acid-soluble spore proteins (ASSPs) comprise about 5% of the total protein of mature spores of different Bacillus subtilis strains. They consist of three abundant species, alpha, beta, and gamma, four less abundant species, and several minor species, alpha, beta, and gamma make up about 18, 18 and 36%, respectively, of the total ASSPs of strain 168, have molecular weights of 5,900, 5,9000, and 11,000, respectively, and resemble the major (A, C, and B) components of Bacillus megaterium ASSPs in several respects, including sensitivity to a specific B. megaterium spore endopeptidase. However, they have pI's of 6.58, 6.67, and 7.96, all lower than those of any of the B. megaterium ASSPs. Although strains varied in the proportions of different ASSPs, to overall patterns seen on gel electrophoresis are constant. ASSPs are located interior to the cortex, presumably in the spore cytoplasm, and are synthesized during sporulation and degraded during germination.