Alanine germination receptors of Bacillus subtilis

OBJECTIVES: To evaluate total visceral adipose tissue (AT) volumes in relation to single slices of visceral AT area measured at different levels and to other simple anthropometric measurements. DESIGN: Only outpatients examined in a metabolic unit were considered; subjects without conditions known to affect AT distribution who gave their informed consent were recruited. SETTING: All subjects were hospitalized in the Department of Internal Medicine of the University of Messina. SUBJECTS: 90 adult subjects of which 18 men and 42 pre- and 30 post-menopausal women. Ages ranged from 18 to 69 years and body mass indexes ranged from 22 to 50. INTERVENTIONS: The AT volume was calculated by computed tomography from the AT area of five scans and from the distances between these scans. RESULTS: AT area at the level of the 2nd-3rd lumbar vertebra had by itself the highest predictive power in men (s.e. = 6.8%), in post-menopausal women (s.e. = 7.4%) and, together with age, in pre-menopausal women (s.e. = 14%). Of the non-radiological parameters it was waist circumference, together with age, which showed the highest predictive power in men (s.e. = 21%), pre-menopausal women (s.e. = 25%) and, together with height, in post-menopausal women (s.e. = 33%). CONCLUSIONS: A single scan measurement at the lumbar level was confirmed to be representative of total visceral AT volume. Waist circumference was the non-radiological parameter that best correlated with volume.     

Kinase-phosphatase competition regulates Bacillus subtilis development

The major regulator of sporulation initiation in Bacillus subtilis is the phosphorelay, a multicomponent signal transduction system. A myriad of signals, both positive and negative, from the environment, cell cycle and metabolism is received and interpreted by the phosphorelay and integrated through the opposing activity of protein kinases and protein aspartate phosphatases to create an extremely sophisticated regulatory network.     

Bacillus subtilis N-acetylmuramic acid L-alanine amidase

The N-acetymuramic acid L-alanine amidase from Bacillus subtilis (ATCC 6051) has been purified to homogeneity. It is a monomeric protein of molecular weight 50,000. The enzyme has a high affinity for homologous cell walls and once attached to a cell wall will hydrolyze the wall completely before initiating the hydrolysis of a new cell wall. The affinity of the enzyme for cell walls devoid of teichoic acid or for cell walls of Bacillus megaterium is much lower than that for B. subtilis cell walls. A second homogenous protein has been isolated from B. subtilis which specifically combines with the amidase in a 1:1 molar ratio and stimulates enzyme activity. This modifier protein has no intrinsic cell wall lytic activity. The binding of enzyme and modifier protein has a dissociation constant of 8.5 times 10-9 M in 0.1 M LiCl, pH 8.0, but the two proteins can be completely dissociated in 3 M LiCl at pH 8.0.     

Selective messenger translation by Bacillus subtilis ribosomes

The in vitro B. subtilis protein synthesizing system is very restricted in its ability to translate E. coli phage messenger RNA's, specifically phage T4 RNA, even though it actively translates its proper mRNA species. In contrast, the E. coli system translates with similar efficiency mRNA from either source. The initiation factors from the two systems are functionally interchangeable. The 30S B. subtilis ribosomal subunit is responsible for the limited template specificity of the B. subtilis ribosomes. Although the efficiency of the T4RNA directed F Met-tRNA binding by B. subtilis ribosomes is less than that of SPOI RNA-directed binding, the most restrictive step in the translation of T4RNA by B. subtilis ribosomes appears to be at the level of the formation of the first peptide bond, as measured by F Metpuromycin formation.     

Aminoacyl-tRNA synthetase gene regulation in Bacillus subtilis

In this review, we summarize progress on the regulation of the aminoacyl-tRNA synthetase genes in Bacillus subtilis. Most of the genes encoding this set of enzymes in B subtilis are members of a large family of Gram-positive genes and operons controlled by a novel antitermination mechanism that uses their cognate uncharged tRNA as the effector. A subset of these genes is, in addition, likely to be controlled at the level of mRNA processing and degradation. We describe the key experiments leading to these conclusions.     

The complete genome sequence of the gram-positive bacterium Bacillus subtilis

Bacillus subtilis is the best-characterized member of the Gram-positive bacteria. Its genome of 4,214,810 base pairs comprises 4,100 protein-coding genes. Of these protein-coding genes, 53% are represented once, while a quarter of the genome corresponds to several gene families that have been greatly expanded by gene duplication, the largest family containing 77 putative ATP-binding transport proteins. In addition, a large proportion of the genetic capacity is devoted to the utilization of a variety of carbon sources, including many plant-derived molecules. The identification of five signal peptidase genes, as well as several genes for components of the secretion apparatus, is important given the capacity of Bacillus strains to secrete large amounts of industrially important enzymes. Many of the genes are involved in the synthesis of secondary metabolites, including antibiotics, that are more typically associated with Streptomyces species. The genome contains at least ten prophages or remnants of prophages, indicating that bacteriophage infection has played an important evolutionary role in horizontal gene transfer, in particular in the propagation of bacterial pathogenesis.     

Homology in natural cryptic plasmids of Bacillus subtilis

Peculiarities of DNA homology in a number of cryptic plasmids isolated from soil bacillary strains and related or identical to Bacillus subtilis were studied. Fragments generated after digestion of one of these plasmids, p1414, were employed as a probe for blot hybridization with identical fragments of other plasmids. The data obtained suggest that nearly all the studied plasmids possess a common homology site that occupies a significant plasmid portion. Regions of detectable and weak homology were located throughout this site. Moreover, plasmid p1414 was shown to carry a large site that lacks homology with plasmids belonging to two groups. Eventually, one of these plasmids demonstrates complete lack of homology with the remaining plasmids.     

Sensitivity of synchronous cultures of Bacillus subtilis to lysozyme

Rates of lysis by lysozyme (expressed as the decrease in A550 min-1) of synchronously dividing cells of Bacillus subtilis rose in concert with the stepwise increase in cell numbers. Asynchronously growing cells showed no periodicities in sensitivity; rates of lysis reflected the exponential increase in culture density.     

Studies on bacillomycin D biosynthesis by Bacillus subtilis

The biosynthesis of bacillomycin D, an antibiotic containing a beta-amino fatty acid and a peptide moiety with asparagine, glutamic acid, serine, proline, threonine, and tyrosine, was studied by incubating the Bacillus subtilis producer with various 14C-labelled precursors. Sodium acetate was incorporated into beta-amino fatty acids of bacillomycin D, and asparagine was the best precursor of the peptidic moiety. The kinetics of the incorporation of radioactive substrates into bacillomycin D and into beta-amino fatty acids show that the lipid and the peptide moieties of the antibiotic were synthesized at the same stage of growth of the bacteria. Comparing the effects of different inhibitors on the incorporation of radioactive precursors, the bacillomycin D and beta-amino fatty acids biosyntheses are discussed in relation to the biosyntheses of proteins, lipids and with sporulation.     

Characterization of polyamine synthesis pathway in Bacillus subtilis 168

Wnt-1, a secreted glycoprotein, participates in development of the nervous system and contributes to mammary oncogenesis when overexpressed. We show that GSK3 activity is decreased in mouse mammary cells transformed by Wnt-1. These cells also exhibit a substantial Wnt-1 dependent increase in the uncomplexed population of beta-catenin. Wnt-1 signaling does not change the steady state level of either GSK3 alpha or GSK3 beta but instead leads to an increased association between GSK3 beta and beta-catenin. HGF/SF treatment of mouse mammary cells also leads to a transient decrease in GSK3 activity and a parallel, selective increase in the uncomplexed pool of beta-catenin. Both Wnt-1 and HGF/SF lead to nuclear accumulation of beta-catenin and activation of a LEF/Tcf responsive reporter gene. This study defines a pivotal signal transduction pathway, activated by both Wnt-1 and HGF/SF, leading to decreased GSK3 beta activity and consequently an increase in the free pool and nuclear accumulation of beta-catenin and changes in gene expression.