Khouri HM

References (5)

Title : Adaptations to submarine hydrothermal environments exemplified by the genome of Nautilia profundicola - Campbell_2009_PLoS.Genet_5_e1000362
Author(s) : Campbell BJ , Smith JL , Hanson TE , Klotz MG , Stein LY , Lee CK , Wu D , Robinson JM , Khouri HM , Eisen JA , Cary SC
Ref : PLoS Genet , 5 :e1000362 , 2009
Abstract : Submarine hydrothermal vents are model systems for the Archaean Earth environment, and some sites maintain conditions that may have favored the formation and evolution of cellular life. Vents are typified by rapid fluctuations in temperature and redox potential that impose a strong selective pressure on resident microbial communities. Nautilia profundicola strain Am-H is a moderately thermophilic, deeply-branching Epsilonproteobacterium found free-living at hydrothermal vents and is a member of the microbial mass on the dorsal surface of vent polychaete, Alvinella pompejana. Analysis of the 1.7-Mbp genome of N. profundicola uncovered adaptations to the vent environment--some unique and some shared with other Epsilonproteobacterial genomes. The major findings included: (1) a diverse suite of hydrogenases coupled to a relatively simple electron transport chain, (2) numerous stress response systems, (3) a novel predicted nitrate assimilation pathway with hydroxylamine as a key intermediate, and (4) a gene (rgy) encoding the hallmark protein for hyperthermophilic growth, reverse gyrase. Additional experiments indicated that expression of rgy in strain Am-H was induced over 100-fold with a 20 degrees C increase above the optimal growth temperature of this bacterium and that closely related rgy genes are present and expressed in bacterial communities residing in geographically distinct thermophilic environments. N. profundicola, therefore, is a model Epsilonproteobacterium that contains all the genes necessary for life in the extreme conditions widely believed to reflect those in the Archaean biosphere--anaerobic, sulfur, H2- and CO2-rich, with fluctuating redox potentials and temperatures. In addition, reverse gyrase appears to be an important and common adaptation for mesophiles and moderate thermophiles that inhabit ecological niches characterized by rapid and frequent temperature fluctuations and, as such, can no longer be considered a unique feature of hyperthermophiles.
ESTHER : Campbell_2009_PLoS.Genet_5_e1000362
PubMedSearch : Campbell_2009_PLoS.Genet_5_e1000362
PubMedID: 19197347
Gene_locus related to this paper: naupa-b9l8q7 , naupa-b9l9g8 , naupa-metxa

Title : Comparative genomic evidence for a close relationship between the dimorphic prosthecate bacteria Hyphomonas neptunium and Caulobacter crescentus - Badger_2006_J.Bacteriol_188_6841
Author(s) : Badger JH , Hoover TR , Brun YV , Weiner RM , Laub MT , Alexandre G , Mrazek J , Ren Q , Paulsen IT , Nelson KE , Khouri HM , Radune D , Sosa J , Dodson RJ , Sullivan SA , Rosovitz MJ , Madupu R , Brinkac LM , Durkin AS , Daugherty SC , Kothari SP , Giglio MG , Zhou L , Haft DH , Selengut JD , Davidsen TM , Yang Q , Zafar N , Ward NL
Ref : Journal of Bacteriology , 188 :6841 , 2006
Abstract : The dimorphic prosthecate bacteria (DPB) are alpha-proteobacteria that reproduce in an asymmetric manner rather than by binary fission and are of interest as simple models of development. Prior to this work, the only member of this group for which genome sequence was available was the model freshwater organism Caulobacter crescentus. Here we describe the genome sequence of Hyphomonas neptunium, a marine member of the DPB that differs from C. crescentus in that H. neptunium uses its stalk as a reproductive structure. Genome analysis indicates that this organism shares more genes with C. crescentus than it does with Silicibacter pomeroyi (a closer relative according to 16S rRNA phylogeny), that it relies upon a heterotrophic strategy utilizing a wide range of substrates, that its cell cycle is likely to be regulated in a similar manner to that of C. crescentus, and that the outer membrane complements of H. neptunium and C. crescentus are remarkably similar. H. neptunium swarmer cells are highly motile via a single polar flagellum. With the exception of cheY and cheR, genes required for chemotaxis were absent in the H. neptunium genome. Consistent with this observation, H. neptunium swarmer cells did not respond to any chemotactic stimuli that were tested, which suggests that H. neptunium motility is a random dispersal mechanism for swarmer cells rather than a stimulus-controlled navigation system for locating specific environments. In addition to providing insights into bacterial development, the H. neptunium genome will provide an important resource for the study of other interesting biological processes including chromosome segregation, polar growth, and cell aging.
ESTHER : Badger_2006_J.Bacteriol_188_6841
PubMedSearch : Badger_2006_J.Bacteriol_188_6841
PubMedID: 16980487
Gene_locus related to this paper: hypna-q0bwt8 , hypna-q0bwv5 , hypna-q0bww7 , hypna-q0bxb2 , hypna-q0bxr5 , hypna-q0by84 , hypna-q0byl3 , hypna-q0bz23 , hypna-q0bzi5 , hypna-q0c0f7 , hypna-q0c0f8 , hypna-q0c2v8 , hypna-q0c2w1 , hypna-q0c2w4 , hypna-q0c3g0 , hypna-q0c4j0 , hypna-q0c4n1 , hypna-q0c4q9 , hypna-q0c4v5 , hypna-q0c386 , hypna-q0c539 , hypna-q0c611

Title : Genome sequence of the PCE-dechlorinating bacterium Dehalococcoides ethenogenes - Seshadri_2005_Science_307_105
Author(s) : Seshadri R , Adrian L , Fouts DE , Eisen JA , Phillippy AM , Methe BA , Ward NL , Nelson WC , DeBoy RT , Khouri HM , Kolonay JF , Dodson RJ , Daugherty SC , Brinkac LM , Sullivan SA , Madupu R , Nelson KE , Kang KH , Impraim M , Tran K , Robinson JM , Forberger HA , Fraser CM , Zinder SH , Heidelberg JF
Ref : Science , 307 :105 , 2005
Abstract : Dehalococcoides ethenogenes is the only bacterium known to reductively dechlorinate the groundwater pollutants, tetrachloroethene (PCE) and trichloroethene, to ethene. Its 1,469,720-base pair chromosome contains large dynamic duplicated regions and integrated elements. Genes encoding 17 putative reductive dehalogenases, nearly all of which were adjacent to genes for transcription regulators, and five hydrogenase complexes were identified. These findings, plus a limited repertoire of other metabolic modes, indicate that D. ethenogenes is highly evolved to utilize halogenated organic compounds and H2. Diversification of reductive dehalogenase functions appears to have been mediated by recent genetic exchange and amplification. Genome analysis provides insights into the organism's complex nutrient requirements and suggests that an ancestor was a nitrogen-fixing autotroph.
ESTHER : Seshadri_2005_Science_307_105
PubMedSearch : Seshadri_2005_Science_307_105
PubMedID: 15637277
Gene_locus related to this paper: dehm1-q3z6q3 , dehm1-q3z6x9 , dehm1-q3z6z2 , dehm1-q3z8f3 , dehm1-q3za50

Title : Complete genome sequence of the Q-fever pathogen Coxiella burnetii - Seshadri_2003_Proc.Natl.Acad.Sci.U.S.A_100_5455
Author(s) : Seshadri R , Paulsen IT , Eisen JA , Read TD , Nelson KE , Nelson WC , Ward NL , Tettelin H , Davidsen TM , Beanan MJ , DeBoy RT , Daugherty SC , Brinkac LM , Madupu R , Dodson RJ , Khouri HM , Lee KH , Carty HA , Scanlan D , Heinzen RA , Thompson HA , Samuel JE , Fraser CM , Heidelberg JF
Ref : Proc Natl Acad Sci U S A , 100 :5455 , 2003
Abstract : The 1,995,275-bp genome of Coxiella burnetii, Nine Mile phase I RSA493, a highly virulent zoonotic pathogen and category B bioterrorism agent, was sequenced by the random shotgun method. This bacterium is an obligate intracellular acidophile that is highly adapted for life within the eukaryotic phagolysosome. Genome analysis revealed many genes with potential roles in adhesion, invasion, intracellular trafficking, host-cell modulation, and detoxification. A previously uncharacterized 13-member family of ankyrin repeat-containing proteins is implicated in the pathogenesis of this organism. Although the lifestyle and parasitic strategies of C. burnetii resemble that of Rickettsiae and Chlamydiae, their genome architectures differ considerably in terms of presence of mobile elements, extent of genome reduction, metabolic capabilities, and transporter profiles. The presence of 83 pseudogenes displays an ongoing process of gene degradation. Unlike other obligate intracellular bacteria, 32 insertion sequences are found dispersed in the chromosome, indicating some plasticity in the C. burnetii genome. These analyses suggest that the obligate intracellular lifestyle of C. burnetii may be a relatively recent innovation.
ESTHER : Seshadri_2003_Proc.Natl.Acad.Sci.U.S.A_100_5455
PubMedSearch : Seshadri_2003_Proc.Natl.Acad.Sci.U.S.A_100_5455
PubMedID: 12704232
Gene_locus related to this paper: coxbu-BIOH , coxbu-CBU0752 , coxbu-CBU1119 , coxbu-CBU1225 , coxbu-CBU1529 , coxbu-CBU1769 , coxbu-CBU1975

Title : The genome sequence of Bacillus anthracis Ames and comparison to closely related bacteria - Read_2003_Nature_423_81
Author(s) : Read TD , Peterson SN , Tourasse N , Baillie LW , Paulsen IT , Nelson KE , Tettelin H , Fouts DE , Eisen JA , Gill SR , Holtzapple EK , Okstad OA , Helgason E , Rilstone J , Wu M , Kolonay JF , Beanan MJ , Dodson RJ , Brinkac LM , Gwinn M , DeBoy RT , Madpu R , Daugherty SC , Durkin AS , Haft DH , Nelson WC , Peterson JD , Pop M , Khouri HM , Radune D , Benton JL , Mahamoud Y , Jiang L , Hance IR , Weidman JF , Berry KJ , Plaut RD , Wolf AM , Watkins KL , Nierman WC , Hazen A , Cline R , Redmond C , Thwaite JE , White O , Salzberg SL , Thomason B , Friedlander AM , Koehler TM , Hanna PC , Kolsto AB , Fraser CM
Ref : Nature , 423 :81 , 2003
Abstract : Bacillus anthracis is an endospore-forming bacterium that causes inhalational anthrax. Key virulence genes are found on plasmids (extra-chromosomal, circular, double-stranded DNA molecules) pXO1 (ref. 2) and pXO2 (ref. 3). To identify additional genes that might contribute to virulence, we analysed the complete sequence of the chromosome of B. anthracis Ames (about 5.23 megabases). We found several chromosomally encoded proteins that may contribute to pathogenicity--including haemolysins, phospholipases and iron acquisition functions--and identified numerous surface proteins that might be important targets for vaccines and drugs. Almost all these putative chromosomal virulence and surface proteins have homologues in Bacillus cereus, highlighting the similarity of B. anthracis to near-neighbours that are not associated with anthrax. By performing a comparative genome hybridization of 19 B. cereus and Bacillus thuringiensis strains against a B. anthracis DNA microarray, we confirmed the general similarity of chromosomal genes among this group of close relatives. However, we found that the gene sequences of pXO1 and pXO2 were more variable between strains, suggesting plasmid mobility in the group. The complete sequence of B. anthracis is a step towards a better understanding of anthrax pathogenesis.
ESTHER : Read_2003_Nature_423_81
PubMedSearch : Read_2003_Nature_423_81
PubMedID: 12721629
Gene_locus related to this paper: bacan-BA0160 , bacan-BA0950 , bacan-BA0954 , bacan-BA1019 , bacan-BA1242 , bacan-BA1727 , bacan-BA1747 , bacan-BA1866 , bacan-BA1914 , bacan-BA2015 , bacan-BA2392 , bacan-BA2417 , bacan-BA2557 , bacan-BA2607 , bacan-BA2687 , bacan-BA2694 , bacan-BA2738 , bacan-BA2865 , bacan-BA3068 , bacan-BA3165 , bacan-BA3178 , bacan-BA3187 , bacan-BA3343 , bacan-BA3372 , bacan-BA3703 , bacan-BA3805 , bacan-BA3863 , bacan-BA3877 , bacan-BA3887 , bacan-BA4324 , bacan-BA4328 , bacan-BA4338 , bacan-BA4577 , bacan-BA4983 , bacan-BA5009 , bacan-BA5110 , bacan-BA5136 , bacan-DHBF , bacan-q81tt2 , bacce-BC0192 , bacce-BC1788 , bacce-BC1954 , bacce-BC2141 , bacce-BC2171 , bacce-BC4730 , bacce-BC4862 , bacce-BC5130 , bacce-PHAC , bacce-q72yu1 , baccr-pepx