A5026657416- Microbial Community Ecology and Physiology
- Genomics and Phylogenetic Studies
- Protist diversity and phylogeny
- Bacteriophages and microbial interactions
- Photosynthetic Processes and Mechanisms
- Bacterial Genetics and Biotechnology
- Photoreceptor and optogenetics research
- Enzyme Structure and Function
- Methane Hydrates and Related Phenomena
- Polar Research and Ecology
- Isotope Analysis in Ecology
- Planetary Science and Exploration
- Origins and Evolution of Life
- Enzyme Production and Characterization
- Spaceflight effects on biology
- RNA and protein synthesis mechanisms
- DNA Repair Mechanisms
- Light effects on plants
- Astro and Planetary Science
- Genetics, Bioinformatics, and Biomedical Research
- Monoclonal and Polyclonal Antibodies Research
- Probiotics and Fermented Foods
- RNA modifications and cancer
- bioluminescence and chemiluminescence research
- Bacterial Infections and Vaccines
University of Maryland, Baltimore
2015-2024
University System of Maryland
2012-2024
Blue Marble Space
2021-2024
Blue Marble Space Institute of Science
2021-2024
University of Maryland, College Park
2014-2024
Institut Pasteur
1987-2021
Columbus Center
2003-2016
Kenyon College
2013
Biotechnology Institute
2003-2009
Institute of Marine Biotechnology
2009
We report the complete sequence of an extreme halophile, Halobacterium sp. NRC-1, harboring a dynamic 2,571,010-bp genome containing 91 insertion sequences representing 12 families and organized into large chromosome 2 related minichromosomes. The NRC-1 codes for 2,630 predicted proteins, 36% which are unrelated to any previously reported. Analysis shows presence pathways uptake utilization amino acids, active sodium-proton antiporter potassium systems, sophisticated photosensory signal...
Abstract Enzymes from extremophilic microorganisms usually catalyze chemical reactions in non-standard conditions. Such conditions promote aggregation, precipitation, and denaturation, reducing the activity of most non-extremophilic enzymes, frequently due to absence sufficient hydration. Some enzymes maintain a tight hydration shell remain active solution even when liquid water is limiting, e.g. presence high ionic concentrations, or at cold temperature close freezing point. Extremophilic...
The genome of the halophilic archaeon Halobacterium sp. NRC-1 and predicted proteome have been analyzed by computational methods reveal characteristics relevant to life in an extreme environment distinguished hypersalinity high solar radiation: (1) is highly acidic, with a median pI 4.9 mostly lacking basic proteins. This characteristic correlates surface negative charge, determined through homology modeling, as major adaptive mechanism proteins function nearly saturating salinity. (2) Codon...
The identification of a universal biosignature that could be sensed remotely is critical to the prospects for success in search life elsewhere universe. A candidate homochirality, which likely generic property all biochemical life. Because optical activity chiral molecules, it has been hypothesized this unique characteristic may provide suitable remote sensing probe using circular polarization spectroscopy. Here, we report detection light scattered by photosynthetic microbes. We show appears...
On November 5–8, 2019, the "Mars Extant Life: What's Next?" conference was convened in Carlsbad, New Mexico. The gathered a community of actively publishing experts disciplines related to habitability and astrobiology. Primary conclusions are as follows: A significant subset attendees concluded that there is realistic possibility Mars hosts indigenous microbial life. powerful theme permeated key search for martian extant life lies identifying exploring refugia ("oases"), where conditions...
To facilitate the functional genomic analysis of an archaeon, we have developed a homologous gene replacement strategy for Halobacterium salinarum based on ura3 , which encodes pyrimidine biosynthetic enzyme orotidine‐5′‐monophosphate decarboxylase. H. was shown to be sensitive 5‐fluoroorotic acid (5‐FOA), can select mutations in . A spontaneous 5‐FOA‐resistant mutant found contain insertion and uracil auxotroph. Integration at bacterioopsin locus ( bop ) this restored 5‐FOA sensitivity...
The genome sequence of Halobacterium sp. strain NRC-1 encodes genes homologous to those responsible for conferring resistance arsenic. These occur on both the large extrachromosomal replicon pNRC100 (arsADRC and arsR2M) chromosome (arsB). We studied role these ars in arsenic genetically by construction gene knockouts. Deletion arsADRC cluster a Deltaura3 resulted increased sensitivity arsenite antimonite but not arsenate. In contrast, knockout chromosomal arsB did show significantly or also...
We have recently characterized a transposable element, ISH1, which inactivates the bacterio-opsin (BO) gene in two purple membrane-deficient (Pum-) mutants of Halobacterium halobium. Examination nine additional Pum- now shows that all these BO has been inactivated by insertion one types elements. Four strains contain ISH1 within gene, probably at same site we previously characterized. A second ISH2, is present four more strains, inserts multiple sites coding sequence. Significantly, another...
We have examined transcripts corresponding to the Halobacterium halobium bacterio-opsin (BO) gene in wild-type and BO-deficient mutant strains containing insertion elements ISH1 or ISH2 BO gene. mRNA from strain was purified by hybrid selection using single-stranded cDNA. Labeling vaccinia virus capping enzyme [alpha-(32)P]GTP showed that it contains 5'-terminal nucleotide of primary transcript. Sequence analysis transcription begins only two nucleotides upstream initiator codon for BO. Two...
Abstract Background Halorubrum lacusprofundi is a cold-adapted halophilic archaeon isolated from Deep Lake, perennially cold and hypersaline lake in Antarctica. Its genome sequencing project was recently completed, providing access to many genes predicted encode polyextremophilic enzymes active both extremely high salinity temperatures. Results Analysis of the sequence H. showed gene cluster for carbohydrate utilization containing glycoside hydrolase family 42 β-galactosidase gene, named bga...
Extremely halophilic archaea, which flourish in hypersaline environments, are known to contain a variety of large dynamic replicons. Previously, the analysis one such replicon, pNRC100, Halobacterium sp. strain NRC-1, showed that it undergoes high-frequency insertion sequence (IS) element-mediated insertions and deletions, as well inversions via recombination between 39-kb-long inverted repeats (IRs). Now, complete sequencing 191,346-bp circle, has shown presence 27 IS elements representing...
ABSTRACT We have investigated anaerobic respiration of the archaeal model organism Halobacterium sp. strain NRC-1 by using phenotypic and genetic analysis, bioinformatics, transcriptome analysis. was found to grow on either dimethyl sulfoxide (DMSO) or trimethylamine N -oxide (TMAO) as sole terminal electron acceptor, with a doubling time 1 day. An operon, dmsREABCD , encoding putative regulatory protein, DmsR, molybdopterin oxidoreductase DMSO reductase family (DmsEABC), molecular chaperone...
Sequenced archaeal genomes contain a variety of bacterial and eukaryotic DNA repair gene homologs, but relatively little is known about how these microorganisms actually perform repair. At least some archaea, including the extreme halophile Halobacterium sp. NRC-1, are able to ultraviolet light (UV) induced damage in absence light-dependent photoreactivation this 'dark' capacity remains largely uncharacterized. NRC-1 possesses homologs uvrA, uvrB, uvrC nucleotide excision genes as well...
Abstract Background The model halophile Halobacterium sp. NRC-1 was among the first Archaea to be completely sequenced and many post-genomic tools, including whole genome DNA microarrays are now being applied its analysis. This extremophile displays tolerance multiple stresses, high salinity, extreme (non-mesophilic) temperatures, lack of oxygen, ultraviolet ionizing radiation. Results In order study response two common stressors, salinity temperature, we used assay for changes in gene...
DeVeaux, L. C., Müller, J. A., Smith, R., Petrisko, J., Wells, D. P. and DasSarma, S. Extremely Radiation-Resistant Mutants of a Halophilic Archaeon with Increased Single-Stranded DNA-Binding Protein (RPA) Gene Expression. Radiat. Res. 168, 507–514 (2007).Extremely halophilic archaea are highly resistant to multiple stressors, including radiation, desiccation salinity. To study the basis stress resistance determine maximum tolerance ionizing we exposed cultures model halophile Halobacterium...