Suprageneric classification of peptidoglycan group B actinomycetes by nucleotide sequencing of 5S ribosomal RNA

5S ribosomal RNA sequences were determined for thirteen actinomycetes mainly representatives with the rare group B type peptidoglycan. The primary and secondary structure of the resultant sequences were of the type characteristic of Gram-positive bacteria with DNA rich in guanine plus cytosine. The sequencing and associated chemotaxonomic data provide compelling grounds for classifying actinomycetes with a group B type peptidoglycan in a single family. The familyMicrobacteriaceae fam. nov. is proposed to accommodate actinomycetes classified in the generaAgromyces, Aureobacterium, Clavibacter, Curtobacterium andMicrobacterium.     

Anthocyanin synthesis in a white flowering mutant of Petunia hybrida

In flower buds of the white flowering mutant W19 of Petunia hybrida four biologically active dihydroflavonol intermediates-dihydroquercetin-7-glucoside, dihydroquercetin-4-glucoside, dihydroquercetin, and dihydrokaempferol-7-glucoside-are accumulated. When dihydroquercetin was supplied to in vitro cultured corollas of the white flowering mutant W18, a mixture of cyanidin and delphinidin glycosides was produced, cyanidin-3-glucoside being the major pigment. The quantity of dihydroquercetin accumulated in W19 is very small, but this compound appears to be a more direct precursor of anthocyanins than the glucosides of dihydrokaempferol and dihydroquercetin. The conditions for pigment synthesis in W18 were optimalized. The quantitative uptake of dihydroquercetin was also studied. It was demonstrated that ca. 1/3 of the quantity present in the culture solution entered the corolla. From the absorbed dihydroquercetin only 14% was converted into anthocyanins. Complementation experiments to determine the biosynthetic sequence of the anthocyanin genes An1, An2, and An3 indicated that the genes An1 and An2 are indistinguishable by this technique.Abbreviation DHQ (+) dihydroquercetin     

Classification ofChlorella strains by infrared absorption spectra of cell samples

The infrared absorption spectra of 29Chlorella strains were recorded over the range from 1,800 to 700 cm⁻¹. Temperature and light intensity upon algal culture gave no significant effect on the spectrum of late log phase cells. The spectra of cells grown in glucose media were different from those of cells grown autotrophically. It was possible to identify 5 groups of strains by comparison of the relative intensities of absorption bands ascribed to nucleic acid, protein, carbohydrate and others, and cell sizes. These groups corresponded well with the current classification ofChlorella.     

Effect of group and isolated rearing of white rats on their resistance to exposure to emotional stress]

The influence of isolated vs. group breeding on the sensitivity of higher nervous and vegetative functions to chronic stress effects was studied in 50 albino random-bred male rats. It has been found that group breeding of the animals (ten specimens in each cage) from the 12th to the 30th week of their life enhances their resistance to external stress factors which begin to take effect from the 17th week on. The effect is linked to the positive emotions produced by mutual contacts among the animals and their intensified motor activity. Isolated breeding of the rats (beginning with the 17th week of their life) makes them vulnerable to the action of stress situations. By the end of the investigation they exhibit clear symptoms of an early stage of neurogenic hypertension. The isolation evidently sets up a negative emotional background, reduces drastically the motor activity and lowers the animals resistance to extreme environmental influences.     

Antibodies to citrullinated proteins and differences in clinical progression of rheumatoid arthritis

Antibodies to citrullinated proteins (anti-cyclic-citrullinated peptide [anti-CCP] antibodies) are highly specific for rheumatoid arthritis (RA) and precede the onset of disease symptoms, indicating a pathogenetic role for these antibodies in RA. We recently showed that distinct genetic risk factors are associated with either anti-CCP-positive disease or anti-CCP-negative disease. These data are important as they indicate that distinct pathogenic mechanisms are underlying anti-CCP-positive disease or anti-CCP-negative disease. Likewise, these observations raise the question of whether anti-CCP-positive RA and anti-CCP-negative RA are clinically different disease entities. We therefore investigated whether RA patients with anti-CCP antibodies have a different clinical presentation and disease course compared with patients without these autoantibodies. In a cohort of 454 incident patients with RA, 228 patients were anti-CCP-positive and 226 patients were anti-CCP-negative. The early symptoms, tender and swollen joint count, and C-reactive protein level at inclusion, as well as the swollen joint count and radiological destruction during 4 years of follow-up, were compared for the two groups. There were no differences in morning stiffness, type, location and distribution of early symptoms, patients' rated disease activity and C-reactive protein at inclusion between RA patients with and without anti-CCP antibodies. The mean tender and swollen joint count for the different joints at inclusion was similar. At follow-up, patients with anti-CCP antibodies had more swollen joints and more severe radiological destruction. Nevertheless, the distribution of affected joints, for swelling, bone erosions and joint space narrowing, was similar. In conclusion, the phenotype of RA patients with or without anti-CCP antibodies is similar with respect to clinical presentation but differs with respect to disease course.     

Identification of the degradome of Isp-1, a major intracellular serine protease of Bacillus subtilis, by two-dimensional gel electrophoresis and matrix- assisted laser desorption/ionization-time of flight analysis

Intracellular serine protease-1 (Isp-1) is a major intracellular serine protease of Bacillus subtilis, whose functions still remain largely unknown. Furthermore, physiological substrates are yet to be determined. To identify Isp-1 substrates, we digested extract obtained from an Isp-1 deficient Bacillus mutant with purified Isp-1 and examined eliminated or decreased spots by two-dimensional gel and matrix-assisted laser desorption/ionization-time of flight analyses. Proteins degraded by Isp-1, termed the Isp-1 degradome, are involved in a variety of cellular functions such as DNA packing, genetic competence, and protein secretion. From the degradome we selected ClpC and EF-Tu as putative Isp-1 substrates and studied their in vitro degradation. ClpC and EF-Tu contain putative cleavage sites for Isp-1. N-terminal sequencing of in vitro proteolytic fragments of ClpC and EF-Tu revealed that these sites are indeed recognized and cleaved by Isp-1. Moreover, the cellular levels of ClpC and EF-Tu were dramatically reduced at the late stationary phase, where the expression level of Isp-1 was greatly increased. These results suggest that the regulated proteolysis of ClpC by Isp-1 plays an important role in the stationary phase adaptive response. This degradomic approach could provide a powerful tool for finding physiological substrates of many proteolytic enzymes whose functions remain to be determined.     

Cloning and characterization of the UDP-sugar hydrolase gene (ushA) of Enterobacter aerogenes IFO 12010

A bacterial alkaline phosphatase (BAP, the phoA gene product) is primarily responsible for the hydrolysis of the substrates 5-bromo-4-chloro-3-indolylphosphate-p-toluidine (XP) and p-nitrophenyl phosphate (pNPP). Using these substrates and an E. coli phoA mutant, we have cloned Enterobacter aerogenes genes conferring an XP(+) phenotype. Two types of clones were identified based on phenotypic tests and DNA sequences. One of them is a E. aerogenes phoA gene (XP(+), pNPP(+)) as expected; surprisingly the other one was found to be a ushA gene (XP(+), pNPP(-)), which encodes an UDP (uridine 5'-diphosphate)-sugar hydrolase. The E. aerogenes ushA gene shares high sequence identity with ushA of E. coli and the mutationally silent ushA0 gene of Salmonella typhimurium at both the nucleotide (over 79%) and amino acid (over 93%) levels. Expression of the E. aerogenes ushA gene in E. coli produced high level of UDP-sugar hydrolase, as confirmed by TLC (thin layer chromatography) analysis together with a presence of a strong band due to a XP hydrolysis on a polyacrylamide gel.