Ribosomal ribonucleic acid synthesis in Bacillus subtilis

The mode of biosynthesis of the 16S and 23S ribosomal ribonucleic acids (rRNA) was studied in Bacillus subtilis 168thy(-). Three criteria were used to define the characteristics of the rRNA species: (i) the time required at 37 degrees C to synthesize 16S and 23S rRNA chains de novo in growing cultures; (ii) the degree of reactivity of the 3'-terminal groups of the rRNA molecules with periodate and [carbonyl-(14)C]isonicotinic acid hydrazide; and (iii) the reactivity of the 5'-terminal regions of the rRNA molecules with the bacterial exonuclease purified by Riley (1969). The 16S and 23S chains of B. subtilis were synthesized at rates of 22+/-2 and 21+/-2 nucleotides added/s. The periodate-[(14)C]isonicotinic acid hydrazide and the exonuclease techniques for estimating apparent chain lengths of RNA indicated that the chain length of the 23S rRNA was 1.8 times that of the 16S fraction. The apparent chain lengths of each rRNA species were: 16S rRNA, 1650+/-50 nucleotide residues; 23S rRNA, 3050+/-90 nucleotide residues. It appears that, the 16S and 23S rRNA molecules in B. subtilis are synthesized in the expected manner, by simple polymerization of the final products on independent cistrons.     

In vitro translation of messenger ribonucleic acid from sporulating and nonsporulating strains of Bacillus subtilis.

An Escherichia coli translation system supplemented with ribonucleic acid from sporulating Bacillus subtilis produces unique polypeptides which are missing among translation products of ribonucleic acid from six early sporulation mutants.     

Genetic analysis of ribonucleic acid polymerase mutants of Bacillus subtilis

Deoxyribonucleic acid-dependent ribonucleic acid polymerase mutants of Bacillus subtilis strain Marburg were isolated after mutagenesis of spores with ethyl methane sulfonate. Genetic analysis by PBS1-mediated transduction and by transformation indicated that mutations responsible for all of the four phenotypic classes studied (rifampin resistance, streptovaricin resistance, streptolydigin resistance, and temperature sensitivity) were clustered close to the cysA14 locus. Three-factor transformation analysis has indicated the most probable marker order as follows: Rif(R)(Stv)(R)-Std(R)-Ts(418)-Ts(427). In addition, further characterization of the classical group I reference marker, cysA14, is reported.     

枯草芽胞杆菌168不对称转化产生磷霉素的蛋白质组学分析

旨在用蛋白质组学方法揭示枯草芽胞杆菌Bacillus subtilis 168将顺丙烯磷酸转化成磷霉素的机理.B.subtilis 168能够将顺丙烯磷酸不对称转化成磷霉素.气相色谱分析发现在转化培养基发酵液中的磷霉素的含量达816.6 tg/mL,转化率为36.05％.将分别培养在含有底物和不含底物的培养基中的B.subtilis 168的胞质蛋白进行双向凝胶电泳.对两种条件下的电泳图谱进行比较,发现有98个差异表达蛋白.其中在有底物存在时,表达量下调的点有20个,表达量上调的点52个,底物特异性表达的点有26个.对差异表达蛋白进行质谱鉴定,共鉴定到80个蛋白点,其中下调的点17个,上调的点45个,底物特异性表达的点18个.这些蛋白分别参与胁迫反应、氧化还原反应、物质转运、核苷酸代谢、糖代谢、氨基酸和蛋白质代谢等.根据上述对B.subtilis 168蛋白质组学分析结果,推测菌株是通过两步将顺丙烯磷酸转化成磷霉素的.第一步是水化反应,第二步是脱氢反应.     

Suppressor system in Bacillus subtilis 168

Multiple auxotrophic strains of Bacillus subtilis 168 were tested for joint one-step reversion of two or more auxotrophic markers to the wild-type phenotype. Mu8u5u5, a strain requiring leucine, methionine, and threonine, yielded revertants that grew without added methionine or threonine and proved to have a suppressor gene. When transferred by transformation with deoxyribonucleic acid, this suppressor gene also suppressed the adenine mutation in another strain, Mu8u5u6. The one-step double revertants fell into two distinct classes: strains of class su(+) (I) grow well in broth; strains of class su(+) (II) grow poorly. Strains su(+) (II) tend to revert frequently to the su(+) (I) or su(-) state. Conditional lethal mutants of phage phie were isolated which can grow on the su(+) and not on the su(-) strains.     

Bacteriophage Interference in Bacillus subtilis 168

Strains of Bacillus subtilis lysogenic for temperate bacteriophage SPO2 inhibit the development of bacteriophage phi1. After infection by bacteriophage phi1, DNA and RNA synthesis in the lysogenic host terminates, culminating in cell death. Bacteriophage SPO2 also prevents the production of bacteriophage phi105. Mechanisms for these two types of bacteriophage interference are discussed.     

Glucocorticoid regulation of proopiomelanocortin messenger ribonucleic acid content of rat hypothalamus

We have verified the possibility that the POMC gene of the rat hypothalamus might be subject to regulation by glucocorticoids. Adrenalectomy increased the concentration of POMC mRNA in anterior pituitary and in hypothalamus, but not in the neurointermediate lobe of the pituitary gland. Dexamethasone and, to a slightly lesser extent, corticosterone treatments reversed the adrenalectomy-induced increase in POMC mRNA concentrations in both anterior pituitary and hypothalamus. Dexamethasone caused a slight decrease of POMC mRNA levels in the neurointermediate lobe of the pituitary gland, while corticosterone had no effect. These results indicate that the POMC gene of the rat brain hypothalamus is also under negative control by glucocorticoids.     

Possible inhibitory effect of teichoic acid on Bacillus subtilis transfer ribonucleic acid

1. tRNA of Bacillus subtilis was found to be variably contaminated with membrane teichoic acid. 2. Samples with high contents of teichoic acid showed no accepting activity for tRNA(Phe) and tRNA(Tyr). 3. Removal of teichoic acid restored accepting activity and fractions containing teichoic acid, separated on Sephadex G-150, inhibited the charging of tRNA(Tyr). 4. The presence of teichoic acid did not inhibit the charging of tRNA(His).     

Heterogeneity of the conserved ribosomal ribonucleic acid sequences of Bacillus subtilis

Doi, Roy H. (University of California, Davis), and Richard T. Igarashi. Heterogeneity of the conserved ribosomal ribonucleic acid sequences of Bacillus subtilis. J. Bacteriol. 92:88-96. 1966.-Hybrid formation was demonstrated between Bacillus subtilis ribosomal ribonucleic acid (RNA) and deoxyribonucleic acid (DNA) from various bacterial species. The high degree of complementarity between B. subtilis ribosomal RNA and the DNA from B. cereus and B. stearothermophilus suggested a method to test whether the same RNA sequences were hybridizing with the DNA from these two species. Saturation studies with 16S and 23S RNA preparations from B. subtilis showed that a definite number of complementary sites was present in each DNA. Base composition analyses of the RNA in the hybrid demonstrated that ribosomal RNA sequences were involved. Hybrid competition studies revealed that B. stearothermophilus ribosomal RNA could compete totally against B. subtilis ribosomal RNA for B. stearothermophilus DNA, although it could compete only partially against the B. subtilis ribosomal RNA hybridizing with B. cereus DNA. These observations were made independently with both 16S and 23S ribosomal RNA preparations. These results revealed that different nucleotide sequences of B. subtilis ribosomal RNA were hybridizing with the DNA from B. cereus and B. stearothermophilus. Two possible interpretations of these results are: (i) different nucleotide sequences from a homogeneous ribosomal RNA population are hybridizing with heterologous DNA preparations, and (ii) ribosomal RNA cistrons are heterogeneous.