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Title: The Genome of the Obligately Intracellular Bacterium Ehrlichia canis Reveals Themes of Complex Membrane Structure and Immune Evasion Strategies

Abstract

Ehrlichia canis, a small obligately intracellular, tick-transmitted, gram-negative, {alpha}-proteobacterium, is the primary etiologic agent of globally distributed canine monocytic ehrlichiosis. Complete genome sequencing revealed that the E. canis genome consists of a single circular chromosome of 1,315,030 bp predicted to encode 925 proteins, 40 stable RNA species, 17 putative pseudogenes, and a substantial proportion of noncoding sequence (27%). Interesting genome features include a large set of proteins with transmembrane helices and/or signal sequences and a unique serine-threonine bias associated with the potential for O glycosylation that was prominent in proteins associated with pathogen-host interactions. Furthermore, two paralogous protein families associated with immune evasion were identified, one of which contains poly(G-C) tracts, suggesting that they may play a role in phase variation and facilitation of persistent infections. Genes associated with pathogen-host interactions were identified, including a small group encoding proteins (n = 12) with tandem repeats and another group encoding proteins with eukaryote-like ankyrin domains (n = 7).

Authors:
 [1];  [2];  [1];  [1];  [1];  [3];  [1];  [4];  [3];  [1];  [1];  [3];  [1];  [2];  [2];  [2];  [1]
  1. U.S. Department of Energy, Joint Genome Institute
  2. Center for Biodenfense and Emerging Infectious Diseases
  3. ORNL
  4. Lawrence Livermore National Laboratory (LLNL)
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org.:
USDOE Office of Science (SC)
OSTI Identifier:
978222
DOE Contract Number:
DE-AC05-00OR22725
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Bacteriology; Journal Volume: 188; Journal Issue: 11
Country of Publication:
United States
Language:
English
Subject:
59 BASIC BIOLOGICAL SCIENCES; 99 GENERAL AND MISCELLANEOUS//MATHEMATICS, COMPUTING, AND INFORMATION SCIENCE; BACTERIA; CHROMOSOMES; DOGS; GENES; MEMBRANES; PROTEINS; RNA

Citation Formats

Mavromatis, K, Doyle, C Kuyler, Lykidis, A, Ivanova, N, Francino, M P, Chain, Patrick S, Shin, M, Malfatti, Stephanie, Larimer, Frank W, Copeland, A, Detter, J C, Land, Miriam L, Richardson, P M, Yu, X J, Walker, D H, McBride, J W, and Kyripides, N C. The Genome of the Obligately Intracellular Bacterium Ehrlichia canis Reveals Themes of Complex Membrane Structure and Immune Evasion Strategies. United States: N. p., 2006. Web. doi:10.1128/JB.01837-05.
Mavromatis, K, Doyle, C Kuyler, Lykidis, A, Ivanova, N, Francino, M P, Chain, Patrick S, Shin, M, Malfatti, Stephanie, Larimer, Frank W, Copeland, A, Detter, J C, Land, Miriam L, Richardson, P M, Yu, X J, Walker, D H, McBride, J W, & Kyripides, N C. The Genome of the Obligately Intracellular Bacterium Ehrlichia canis Reveals Themes of Complex Membrane Structure and Immune Evasion Strategies. United States. doi:10.1128/JB.01837-05.
Mavromatis, K, Doyle, C Kuyler, Lykidis, A, Ivanova, N, Francino, M P, Chain, Patrick S, Shin, M, Malfatti, Stephanie, Larimer, Frank W, Copeland, A, Detter, J C, Land, Miriam L, Richardson, P M, Yu, X J, Walker, D H, McBride, J W, and Kyripides, N C. Sun . "The Genome of the Obligately Intracellular Bacterium Ehrlichia canis Reveals Themes of Complex Membrane Structure and Immune Evasion Strategies". United States. doi:10.1128/JB.01837-05.
@article{osti_978222,
title = {The Genome of the Obligately Intracellular Bacterium Ehrlichia canis Reveals Themes of Complex Membrane Structure and Immune Evasion Strategies},
author = {Mavromatis, K and Doyle, C Kuyler and Lykidis, A and Ivanova, N and Francino, M P and Chain, Patrick S and Shin, M and Malfatti, Stephanie and Larimer, Frank W and Copeland, A and Detter, J C and Land, Miriam L and Richardson, P M and Yu, X J and Walker, D H and McBride, J W and Kyripides, N C},
abstractNote = {Ehrlichia canis, a small obligately intracellular, tick-transmitted, gram-negative, {alpha}-proteobacterium, is the primary etiologic agent of globally distributed canine monocytic ehrlichiosis. Complete genome sequencing revealed that the E. canis genome consists of a single circular chromosome of 1,315,030 bp predicted to encode 925 proteins, 40 stable RNA species, 17 putative pseudogenes, and a substantial proportion of noncoding sequence (27%). Interesting genome features include a large set of proteins with transmembrane helices and/or signal sequences and a unique serine-threonine bias associated with the potential for O glycosylation that was prominent in proteins associated with pathogen-host interactions. Furthermore, two paralogous protein families associated with immune evasion were identified, one of which contains poly(G-C) tracts, suggesting that they may play a role in phase variation and facilitation of persistent infections. Genes associated with pathogen-host interactions were identified, including a small group encoding proteins (n = 12) with tandem repeats and another group encoding proteins with eukaryote-like ankyrin domains (n = 7).},
doi = {10.1128/JB.01837-05},
journal = {Journal of Bacteriology},
number = 11,
volume = 188,
place = {United States},
year = {Sun Jan 01 00:00:00 EST 2006},
month = {Sun Jan 01 00:00:00 EST 2006}
}
  • Ehrlichia canis, a small obligately intracellular, tick-transmitted, gram-negative, a-proteobacterium is the primary etiologic agent of globally distributed canine monocytic ehrlichiosis. Complete genome sequencing revealed that the E. canis genome consists of a single circular chromosome of 1,315,030 bp predicted to encode 925 proteins, 40 stable RNA species, and 17 putative pseudogenes, and a substantial proportion of non-coding sequence (27 percent). Interesting genome features include a large set of proteins with transmembrane helices and/or signal sequences, and a unique serine-threonine bias associated with the potential for O-glycosylation that was prominent in proteins associated with pathogen-host interactions. Furthermore, two paralogous protein familiesmore » associated with immune evasion were identified, one of which contains poly G:C tracts, suggesting that they may play a role in phase variation and facilitation of persistent infections. Proteins associated with pathogen-host interactions were identified including a small group of proteins (12) with tandem repeats and another with eukaryotic-like ankyrin domains (7).« less
  • No abstract prepared.
  • The complete genome sequence of Thiobacillus denitrificans ATCC 25259 is the first to become available for an obligately chemolithoautotrophic, sulfur-compound-oxidizing, {beta}-proteobacterium. Analysis of the 2,909,809-bp genome will facilitate our molecular and biochemical understanding of the unusual metabolic repertoire of this bacterium, including its ability to couple denitrification to sulfur-compound oxidation, to catalyze anaerobic, nitrate-dependent oxidation of Fe(II) and U(IV), and to oxidize mineral electron donors. Notable genomic features include (i) genes encoding c-type cytochromes totaling 1 to 2 percent of the genome, which is a proportion greater than for almost all bacterial and archaeal species sequenced to date, (ii) genesmore » encoding two [NiFe]hydrogenases, which is particularly significant because no information on hydrogenases has previously been reported for T. denitrificans and hydrogen oxidation appears to be critical for anaerobic U(IV) oxidation by this species, (iii) a diverse complement of more than 50 genes associated with sulfur-compound oxidation (including sox genes, dsr genes, and genes associated with the AMP-dependent oxidation of sulfite to sulfate), some of which occur in multiple (up to eight) copies, (iv) a relatively large number of genes associated with inorganic ion transport and heavy metal resistance, and (v) a paucity of genes encoding organic-compound transporters, commensurate with obligate chemolithoautotrophy. Ultimately, the genome sequence of T. denitrificans will enable elucidation of the mechanisms of aerobic and anaerobic sulfur-compound oxidation by {beta}-proteobacteria and will help reveal the molecular basis of this organism's role in major biogeochemical cycles (i.e., those involving sulfur, nitrogen, and carbon) and groundwater restoration.« less
  • Thioalkalivibrio paradoxus strain ARh 1 T is a chemolithoautotrophic, non-motile, Gram-negative bacterium belonging to the Gammaproteobacteria that was isolated from samples of haloalkaline soda lakes. It derives energy from the oxidation of reduced sulfur compounds and is notable for its ability to grow on thiocyanate as its sole source of electrons, sulfur and nitrogen. The full genome consists of 3,756,729 bp and comprises 3,500 protein-coding and 57 RNA-coding genes. Moreover, this organism was sequenced as part of the community science program at the DOE Joint Genome Institute.