A5020107528- Photosynthetic Processes and Mechanisms
- Microbial Community Ecology and Physiology
- Streptococcal Infections and Treatments
- Antimicrobial Resistance in Staphylococcus
- Algal biology and biofuel production
- Bacterial Identification and Susceptibility Testing
- Genomics and Phylogenetic Studies
- Bacterial Genetics and Biotechnology
- Legume Nitrogen Fixing Symbiosis
- Microbial Fuel Cells and Bioremediation
- Neonatal and Maternal Infections
- Light effects on plants
- Infective Endocarditis Diagnosis and Management
- Fungal and yeast genetics research
- Porphyrin Metabolism and Disorders
- Protist diversity and phylogeny
- Infections and bacterial resistance
- Enzyme Structure and Function
- RNA and protein synthesis mechanisms
- Animal Genetics and Reproduction
- Milk Quality and Mastitis in Dairy Cows
- Escherichia coli research studies
- Microbial infections and disease research
- Free Radicals and Antioxidants
- Bacterial biofilms and quorum sensing
Houston Methodist
1993-2024
Methodist Hospital
2022-2024
Cornell University
2022-2024
The University of Texas at Austin
1992-2014
The University of Texas Health Science Center at Houston
1996-2011
Texas Medical Center
2007
The University of Texas System
2005
Weatherford College
1993
A new locus, prrA, involved in the regulation of photosynthesis gene expression response to oxygen, has been identified Rhodobacter sphaeroides. Inactivation prrA results absence photosynthetic spectral complexes. The product strong homology regulators associated with signal transduction other prokaryotes. When is present multiple copies, cells produce light-harvesting complexes under aerobic growth conditions, suggesting that affects positively oxygen deprivation. Analysis puc::lacZ fusions...
Two new loci, prrB and prrC, involved in the positive regulation of photosynthesis gene expression response to anaerobiosis, have been identified Rhodobacter sphaeroides. encodes a sensor histidine kinase that is responsive removal oxygen functions through regulator PrrA. Inactivation results substantial reduction photosynthetic spectral complexes as well inability cells grow photosynthetically at low medium light intensities. Together, prrA provide major signal synthesis specialized...
In Escherichia coli, FtsN localizes late to the cell division machinery, only after a number of additional essential proteins are recruited early FtsZ-FtsA-ZipA complex. has short, positively charged cytoplasmic domain (FtsN(Cyto)), single transmembrane (FtsN(TM)), and periplasmic that is for function. Here we show FtsA interact directly in vitro. FtsN(Cyto) sufficient bind FtsA, but when it tethered FtsN(TM) or leucine zipper. Mutation conserved patch positive charges negative abolishes...
The mraZ and mraW genes are highly conserved in bacteria, both sequence their position at the head of division cell wall (dcw) gene cluster. Located directly upstream gene, Pmra promoter drives transcription mraW, as well many essential genes, but no regulator has been found to date. Although MraZ structural similarity AbrB transition state MazE antitoxin MraW is known methylate 16S rRNA, null mutants have detectable phenotypes. Here we show that overproduction Escherichia coli inhibited was...
Necrotizing fasciitis and myositis are devastating infections characterized by high mortality. Group A streptococcus (GAS) is a common cause of these infections, but the molecular pathogenesis poorly understood. We report genome-wide analysis using serotype M1 M28 strains that identified GAS genes contributing to necrotizing in nonhuman primates (NHP), clinically relevant model. Using transposon-directed insertion-site sequencing (TraDIS), we 126 116 required for infection organisms,...
Activation of photosynthesis (PS) gene expression by the PrrBA two-component activation system in Rhodobacter sphaeroides 2.4.1 results from interruption an inhibitory signal originating cbb3 cytochrome c oxidase via its interaction with oxygen, conjunction Rdx redox proteins. The CcoQ protein, encoded ccoNOQP operon, which encodes oxidase, was shown to act as a "transponder" that conveys derived reductant flow through Prr system. To further define elements comprising this transduction...
Rhodobacter sphaeroides 2.4.1 is a member of the nonsulfur purple facultative photosynthetic proteobacteria, capable growth under variety cultivation conditions. In addition to structural polypeptides and bacteriochlorophyll, two major antenna complexes, B875 B800-850, contain carotenoids which are an important functional component membrane-bound complexes this bacterium. Two carotenoids, spheroidene its keto derivative, spheroidenone, differentially synthesized by R. sphaeroides, depending...
ABSTRACT To further understand the proposed signal transduction pathway involving presumed redox proteins RdxBH and cbb 3 cytochrome oxidase in Rhodobacter sphaeroides 2.4.1, a series of mutants lacking components both Prr two-component activation system -type or were constructed. We report that under highly aerobic conditions, aberrant photosynthesis gene expression spectral complex formation typical - RdxBH-deficient no longer observed when either prrA (encoding response regulator system)...
ABSTRACT FnrL, the homolog of global anaerobic regulator Fnr, is required for induction photosynthetic apparatus in Rhodobacter sphaeroides 2.4.1. Thus, precise role FnrL photosynthesis (PS) gene expression and its interaction(s) with other regulators PS are considerable importance to our understanding regulatory circuitry governing spectral complex formation. Using a CcoP double mutant strain, we obtained results which suggested that not involved transduction inhibitory signal, by...
The PrrBA two-component regulatory system is a major global regulator in Rhodobacter sphaeroides 2.4.1. Here we have compared the transcriptome and proteome profiles of wild-type (WT) mutant PrrA2 cells grown anaerobically dark with dimethyl sulfoxide as an electron acceptor. Approximately 25% genes present genome are regulated by PrrA at transcriptional level, either directly or indirectly, twofold more relative to WT. affected widespread throughout all COG (cluster orthologous group)...
The ability to detect regulatory elements within genome sequences is important in understanding how gene expression controlled biological systems. In this work, microarray data analysis combined with sequence predict DNA the photosynthetic bacterium Rhodobacter sphaeroides that bind regulators PrrA, PpsR and FnrL. These predictions were made by using hierarchical clustering genes share similar patterns. upstream of these then searched for possible transcription factor recognition motifs may...
Necrotizing myositis caused by Streptococcus pyogenes has high morbidity and mortality rates relatively few successful therapeutic options. In addition, there is no licensed human S. vaccine. To gain enhanced understanding of the molecular basis this infection, we employed a multidimensional analysis strategy that included dual RNA-seq other data derived from experimental infection nonhuman primates. The were used to target five streptococcal genes for pathogenesis research, resulting in...
Streptococcus dysgalactiae subsp. equisimilis is a bacterial pathogen that increasingly recognized as cause of severe human infections. Much less known about the genomics and infection pathogenesis S. strains compared to closely related bacterium pyogenes. To address these knowledge deficits, we sequenced closure genomes seven isolates, including six were emm type stG62647. Recently, for unknown reasons, this have emerged caused an increasing number infections in several countries. The vary...
Expression of the cea gene, which is carried by ColE1 plasmid and encodes colicin E1, was found to be greatly increased when cells were grown anaerobically. By using cea-lacZ fusions quantitate expression, aerobic levels only a few percent anaerobic levels. The increase in expression observed both protein operon fusions, indicating that its regulation occurred at level transcription. It also require functional fnr gene occur fusion present as single copy bacterial chromosome instead...
To obtain new information about Streptococcus pyogenes intrahost genetic variation during invasive infection, we sequenced the genomes of 2,954 serotype M1 strains recovered from a nonhuman primate experimental model necrotizing fasciitis. A total 644 (21.8%) acquired polymorphisms relative to input parental strain. The fabT gene, encoding transcriptional regulator fatty acid biosynthesis genes, contained 54.5% these changes. great majority were predicted deleteriously alter FabT function....
Rhodobacter sphaeroides 2.4.1 synthesizes a specialized photosynthetic membrane upon reduction of the O2 tension below threshold levels. The genes prrB and prrA encode sensor kinase response regulator, respectively, two-component regulatory system that presumably is involved in transduction signal(s) monitors alterations oxygen A third gene, prrC, also this cascade events. Previously, we described mutant form PrrB, namely, PrrB78 (J. M. Eraso S. Kaplan, J. Bacteriol. 177:2695-2706, 1995),...
Regulation of photosynthetic membrane synthesis in Rhodobacter sphaeroides 2.4.1 is dependent on the interactions numerous regulatory elements, with two most important being cbb(3) terminal oxidase and PrrBAC two-component system. Here, we reveal that possesses extensive, additional activities under anaerobic conditions, system further involved regulation expression more than 20% R. genome extending well beyond functions related to redox gene expression.
The facultative photosynthetic bacterium Rhodobacter sphaeroides 2.4.1 has a nitric oxide-response transcriptional regulator, NnrR, and oxide reductase (NOR), although it is incapable of denitrification. To investigate at the genomic level physiological response to nitrosative stress R. sphaeroides, transcriptome profiles strain its NnrR mutant were analyzed before after exposure nitrosating agents, S-nitrosoglutathione (GSNO) sodium nitroprusside (SNP), under microaerobic conditions. GSNO...
The synthesis of colicin E1 is known to be regulated by the SOS response, anaerobiosis, and catabolite repression. expression cea-lacZ fusions was also found stimulated when cells reached stationary phase. This increase in determined due depletion nutrients from medium, since addition fresh medium reversed effect. Expression fusion increased were starved 10 mM MgSO4 they grown conditioned which had been previously. stimulation occurred present single-copy as well multicopy plasmids. Finally,...
ABSTRACT The expression of genes involved in photosystem development Rhodobacter sphaeroides is dependent upon three major regulatory networks: FnrL, the PrrBA (RegBA) two-component system, and transcriptional repressor/antirepressor PpsR/AppA. Of regulators, PpsR appears to have narrowest range physiological effects, which are limited effects on structural pigment biosynthetic activities photosynthetic membrane function. Although a PrrA − mutant unable grow under conditions, when ppsR...
In the present study, we show in vitro binding of PrrA, a global regulator Rhodobacter sphaeroides 2.4.1, to PrrA site 2, within RSP3361 locus. Specific binding, as shown by competition experiments, requires phosphorylation PrrA. The affinity for 2 was found increase 4- 10-fold when spermidine added reaction. presence extracellular concentrations growing cultures R. gave rise twofold expression photosynthesis genes pucB and pufB, well gene, under aerobic growth conditions, use lacZ...
Serotype M28 group A streptococcus (GAS) is a common cause of infections such as pharyngitis (“strep throat”) and necrotizing fasciitis (“flesh-eating” disease). Relatively little known about the molecular mechanisms underpinning GAS pathogenesis.