Phylogenetic, amino acid content and indel analyses of the beta subunit of DNA-dependent RNA polymerase of Gram-positive and Gram-negative bacteria

2002 ◽  
Vol 52 (5) ◽  
pp. 1477-1484 ◽  
Author(s):  
R. Morse
1999 ◽  
Vol 43 (5) ◽  
pp. 1274-1276 ◽  
Author(s):  
Manhong Wu ◽  
Robert E. W. Hancock

ABSTRACT Both linear and cyclic derivatives of the cyclic 12-amino-acid antimicrobial peptide bactenecin were designed based on optimization of amphipathicity and charge location. In general, increasing the number of positive charges at the N and C termini and adding an extra tryptophan residue in the loop not only increased the activities against both gram-positive and gram-negative bacteria but also broadened the antimicrobial spectrum.


2021 ◽  
Vol 9 ◽  
pp. 3-33
Author(s):  
V. I. Silaev ◽  
◽  
A. V. Kokin ◽  
N. V. Pavlovich ◽  
S. N. Shanina ◽  
...  

We studied 14 samples of gram-negative and gram-positive bacteria, unicellular yeasts and green algae using optical, atomic force and analytical scanning electron microscopy, thermal analysis, gas chromatography, infrared spectroscopy, inductively coupled plasma mass spectrometry and isotope mass spectrometry. In shape, the cells of microorganisms vary from rod-shaped to lenticular and coccoid, in size they range from mesonanometer to micrometer. A strong positive correlation was found between the extreme cell sizes. An admixture of inorganic chemical elements — Mg, Ca, Ba, Na, K, Cu, Zn, P, S, Cl and submicron-sized precipitates of mineral phases — carbonates, phosphate sulfates, hydrogen sulfate phosphates, hydrogen phosphates, halite, kaolinite, was found in the chemical composition of the studied microorganisms, metal alloys of brass composition, baddeleyite. Among the 45 microelements identified in microorganisms, there were 7 essential elements (E), 17 physiogenically active (FA) and 19 abiotic (AB). The total concentration of trace elements ranged from 0.003—0.26 wt. %. The value of the essential coefficient — E / AB — averaged 196 ± 153. Microorganisms were characterized by a mixed fat-protein elemental composition, they contained 14 amino acids belonging to the aliphatic, aromatic, basic, acidic, hydroxyl, imino and sulfur-containing groups. The total amino acid content ranged from 409 to 942 (682 ± 221) mg/g. Up to half of the amino acids were represented by the left (L) and right (D) enantiomers. The degree of racemization (D / L) ranged from 0.01 to 0.37. Yeast and chlorella were characterized by the most isotopically heavy composition of carbon in combination with relatively isotopically light nitrogen. In bacteria, a statistically lighter carbon was found in combination with a much heavier nitrogen. According to a number of properties — the chemical composition of organic matter, microelements, the degree of enrichment with antibiotic elements, the content of amino acids and the degree of their racemization — gram-negative and gram-positive bacteria differed. In general, the studied biological microorganisms were fundamentally different from the abiogenic organic substances found in meteorites and products of modern volcanism regarding their elemental and amino acid composition, carbon and nitrogen isotopes.


2016 ◽  
Vol 199 (2) ◽  
Author(s):  
Andy Weiss ◽  
Brittney D. Moore ◽  
Miguel H. J. Tremblay ◽  
Dale Chaput ◽  
Astrid Kremer ◽  
...  

ABSTRACT Staphylococcus aureus is a major human pathogen that causes infection in a wide variety of sites within the human body. Its ability to adapt to the human host and to produce a successful infection requires precise orchestration of gene expression. While DNA-dependent RNA polymerase (RNAP) is generally well characterized, the roles of several small accessory subunits within the complex have yet to be fully explored. This is particularly true for the omega (ω or RpoZ) subunit, which has been extensively studied in Gram-negative bacteria but largely neglected in Gram-positive counterparts. In Escherichia coli, it has been shown that ppGpp binding, and thus control of the stringent response, is facilitated by ω. Interestingly, key residues that facilitate ppGpp binding by ω are not conserved in S. aureus, and consequently, survival under starvation conditions is unaffected by rpoZ deletion. Further to this, ω-lacking strains of S. aureus display structural changes in the RNAP complex, which result from increased degradation and misfolding of the β′ subunit, alterations in δ and σ factor abundance, and a general dissociation of RNAP in the absence of ω. Through RNA sequencing analysis we detected a variety of transcriptional changes in the rpoZ-deficient strain, presumably as a response to the negative effects of ω depletion on the transcription machinery. These transcriptional changes translated to an impaired ability of the rpoZ mutant to resist stress and to fully form a biofilm. Collectively, our data underline, for the first time, the importance of ω for RNAP stability, function, and cellular physiology in S. aureus. IMPORTANCE In order for bacteria to adjust to changing environments, such as within the host, the transcriptional process must be tightly controlled. Transcription is carried out by DNA-dependent RNA polymerase (RNAP). In addition to its major subunits (α2ββ′) a fifth, smaller subunit, ω, is present in all forms of life. Although this small subunit is well studied in eukaryotes and Gram-negative bacteria, only limited information is available for Gram-positive and pathogenic species. In this study, we investigated the structural and functional importance of ω, revealing key roles in subunit folding/stability, complex assembly, and maintenance of transcriptional integrity. Collectively, our data underline, for the first time, the importance of ω for RNAP function and cellular harmony in S. aureus.


Molecules ◽  
2019 ◽  
Vol 25 (1) ◽  
pp. 105 ◽  
Author(s):  
Rakia Abd Alhameed ◽  
Zainab Almarhoon ◽  
Sarah I. Bukhari ◽  
Ayman El-Faham ◽  
Beatriz G. de la Torre ◽  
...  

Novel thiazolidine-2,4-dione carboxamide and amino acid derivatives were synthesized in excellent yield using OxymaPure/N,N′-diisopropylcarbodimide coupling methodology and were characterized by chromatographic and spectrometric methods, and elemental analysis. The antimicrobial and antifungal activity of these derivatives was evaluated against two Gram-positive bacteria (Staphylococcus aureus and Bacillus subtilis), two-Gram negative bacteria (Escherichia coli and Pseudomonas aeruginosa), and one fungal isolate (Candida albicans). Interestingly, several samples demonstrated weak to moderate antibacterial activity against Gram-negative bacteria, as well as antifungal activity. However, only one compound namely, 2-(5-(3-methoxybenzylidene)-2,4-dioxothiazolidin-3-yl)acetic acid, showed antibacterial activity against Gram-positive bacteria, particularly S. aureus.


Author(s):  
Jacob S. Hanker ◽  
Paul R. Gross ◽  
Beverly L. Giammara

Blood cultures are positive in approximately only 50 per cent of the patients with nongonococcal bacterial infectious arthritis and about 20 per cent of those with gonococcal arthritis. But the concept that gram-negative bacteria could be involved even in chronic arthritis is well-supported. Gram stains are more definitive in staphylococcal arthritis caused by gram-positive bacteria than in bacterial arthritis due to gram-negative bacteria. In the latter situation where gram-negative bacilli are the problem, Gram stains are helpful for 50% of the patients; they are only helpful for 25% of the patients, however, where gram-negative gonococci are the problem. In arthritis due to gram-positive Staphylococci. Gramstained smears are positive for 75% of the patients.


Sign in / Sign up

Export Citation Format

Share Document