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N Lang

Publications and source records attributed to N Lang.

At least 127 records · Page 7Linked to original sources
PubMed1981

Nucleotide sequence of a Bacillus subtilis promoter recognized by Bacillus subtilis RNA polymerase containing sigma 37.

We report the nucleotide sequence of the promoter for a Bacillus subtilis gene (spoVC) whose transcription is controlled by a 37,000 dalton species of B. subtilis sigma factor known as sigma 37 but not by the principal- sigma factor of 55,000 daltons (sigma 55). Using S1 nuclease mapping we show that the startpoint for sigma 37-directed transcription of the spoVC gene in vitro corresponded closely to the 5' terminus of in vivo synthesized spoVC RNA. The binding site for sigma 37-containing RNA polymerase extended from 43 bp to 51 bp (positions -43 to -51) upstream from the transcription startpoint to 22 bp (position +22) downstream from the startpoint. The nucleotide sequence of the spoVC promoter differed significantly from promoters whose recognition is controlled by sigma 55 but was similar to other sigma 37- controlled promoters in regions known to be important in promoter recognition. Our results are consistent with the hypothesis (Lee and Pero, J. Mol. Biol., in press) that sigma factors work by contacting specific bases in both the -35 and -10 regions of promoters.

Bacillus subtilis↗
PubMed1981

A sporulation-induced sigma-like regulatory protein from B. subtilis.

We have isolated a sigma-like regulatory protein termed sigma 29 whose synthesis or association with Bacillus subtilis RNA polymerase was induced during spore formation. sigma 29 is a sporulation-specific component of RNA polymerase as it was absent in enzyme from an early-blocked sporulation mutant (SpoOA). We have demonstrated specific RNA synthesis by sigma 29-RNA polymerase using as a DNA template a cloned cluster of vegetative and sporulation genes from the purA-cysA region of the B. subtilis chromosome. The pattern of gene recognition by sigma 29-RNA polymerase was distinct from that observed for RNA polymerases containing sigma 55 or sigma 37, species of sigma factor that are present in vegetative cells of B. subtilis. A reconstitution experiment in which purified sigma 29 was added to core RNA polymerase demonstrates that sigma 29 was directly responsible for the altered transcriptional specificity of sporulation RNA polymerase. We propose that sigma 29 is a regulatory protein that controls developmental gene transcription at an early stage of spore formation.

Bacillus subtilis↗
PubMed1981

Promoter for a developmentally regulated gene in Bacillus subtilis.

We have determined the nucleotide sequence of the promoter for aB. subtilis gene (the 0.4 kb gene) whose transcription is under developmental control. Transcription of the 0.4 kb gene is turned on at the onset of sporulation; this RNA synthesis depends on the products of the B. subtilis regulatory genes (the spoO loci) that control the initiation of development. Recognition of the 0.4 kb gene promoter in vitro is dictated by novel species of B. subtilis RNA polymerase sigma factor known as sigma 37 and sigma 29 but not by the principal B. subtilis sigma factor sigma 55. Using S1 nuclease mapping, runoff transcription and dinucleotide priming, we have identified dual startpoints (separated by about 10 bp) for sigma37-directed transcription of the 0.4 kb gene These start-points correspond closely to the 5' termini of 0.4 kb RNA synthesized in vivo during the course of sporulation. Two forms of sigma37 containing RNA polymerase were distinguished that preferentially utilize either the upstream or the downstream startpoint in vitro. We investigated the requirements for sigma37-directed transcription by constructing in vitro deletion mutations that extend from the upstream direction into the 0.4 kb promoter region. One such deletion, which terminates 40 and 51 bp upstream from the transcription startpoints (thereby removing a highly AT-rich 26 bp sequence), completely eliminates transcription from the downstream startpoint but only partially inhibits transcription from the upstream startpoint. A second deletion that terminates at the upstream startpoint completely prevents transcription from both initiation sites. The implications of 0.4 kb gene promoter structure for developmentally regulated transcription of B, subtilis are discussed.

Bacillus subtilis↗
PubMed1980

Occurrence of Bacteroidaceae in vaginal secretions of healthy pregnant women and patients with colpitis.

The frequency of gram-negative non-sporing anaerobes with possible clinical significance was studied in healthy pregnant women and in patients with non-Candida vaginitis. Only 4% of the healthy pregnant women studied yielded anaerobes of the family Bacteroidaceae. However, the incidence of Bacteroidaceae in 58 patients with colpitis was 53.5%. The predominant anaerobic species was Bacteroides oralis.

Bacteroidaceae↗
PubMed1980

Diagnosis of pure and mixed anaerobic infections in obstetrics and gynecology.

Less than one third of women patients with post-partum endometritis, abscess formation and similar pathologic conditions were found to have pure anaerobic infection. The majority of the infections were caused by facultative organisms and anaerobes. Bacteroides oralis, Baceroides fragilis and Peptococcaceae were the predominant isolates. Treatment with an anti-microbial agent active against most anerobes led to clinical cure even in cases of mixed infections. This may possibly indicate that anaerobes play an important pathogenic role in female genital tract infections.

Anaerobiosis↗
PubMed1980

[The role of anaerobic bacteria in the post-partum period: clinical significance and treatment (author's transl)].

Anaerobic bacteria in the lochia are frequently isolated healthy post-partum patients and from those with post-partum infections. The true pathogenic significance of these anaerobic bacteria is uncertain. Investigations appeared to show that the incidence of anaerobic bacteria is by and large the same as in the vaginal and intestinal flora. In this investigation we showed: 1) anaerobic bacteria are rare in the vaginal flora of pregnant patients in the third trimester, 2) a definite difference exists in the number of anaerobic bacteria in normal lochia versus infected lochia, 3) in post-partum infections qualitative differences exist between the anaerobic isolates. The strains of the bacteroides oralis group become the predominant anaerobic bacteria. It is concluded that members of the bacteroides oralis group which are normally not present in the human intestinal flora play a specific role in post-partum infections. The anti-microbial treatment of post-partum infections has to take this into account. The eminent therapeutic importance of the 5-Nitro-Imidazoles is discussed.

Anaerobiosis↗
PubMed1978

[On the clinical significance of sequential scintigraphic examinations of the uteroplacental perfusion (author's transl)].

The utero-placental perfusion was examined by means of the method of Hünermann (1972) in a group of 74 patients with toxemia of pregnancy, diabetes mellitus, or intrauterine growth retardation. The perfusion measurements were categorized and evaluated according to the clinical findings. The correlation between single values deriving from the time-activity curves and their clinical predictive value was ascertained. A strong correlation between the parameters and the clinical findings resulted when several criteria were considered simultaneously. Among the single values resulting from the perfusion curves, the Tmax (placenta) and Tmax (uterus) (time of activity maximum) as well as the quotient of both revealed the highest significance. Pathological time-activity-curves were found in 16 of 19 patients with moderate and severe intrauterine growth retardation, and in all patients with moderate and severe toxemia, or diabetes mellitus. The limited clinical value of the used method is discussed.

Asphyxia Neonatorum↗