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Title: Conserved synteny at the protein family level reveals genes underlying Shewanella species cold tolerance and predicts their novel phenotypes

Abstract

Bacteria of the genus Shewanella can thrive in different environments and demonstrate significant variability in their metabolic and ecophysiological capabilities including cold and salt tolerance. Genomic characteristics underlying this variability across species are largely unknown. In this study we address the problem by a comparison of the physiological, metabolic and genomic characteristics of 19 sequenced Shewanella species. We have employed two novel approaches based on association of a phenotypic trait with the number of the trait-specific protein families (Pfam domains) and on the conservation of synteny (order in the genome) of the trait-related genes. Our first approach is top-down and involves experimental evaluation and quantification of the species’ cold tolerance followed by identification of the correlated Pfam domains and genes with a conserved synteny. The second, a bottom-up approach, predicts novel phenotypes of the species by calculating profiles of each Pfam domain among their genomes and following pair-wise correlation of the profiles and their network clustering. Using the first approach we find a link between cold and salt tolerance of the species and the presence in the genome of a Na+/H+ antiporter gene cluster. Other cold tolerance related genes includes peptidases, chemotaxis sensory transducer proteins, a cysteine exporter, and helicases.more » Using the bottom-up approach we found several novel phenotypes in the newly sequenced Shewanella species, including degradation of aromatic compounds by an aerobic hybrid pathway in S. woodyi, degradation of ethanolamine by S. benthica, and propanediol degradation by S. putrefaciens CN32 and S. sp. W3-18-1.« less

Authors:
; ; ; ; ; ; ; ; ; ; ; ;
Publication Date:
Research Org.:
Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
974921
Report Number(s):
PNNL-SA-68633
KP1501021
DOE Contract Number:
AC05-76RL01830
Resource Type:
Journal Article
Resource Relation:
Journal Name: Functional & Integrative Genomics, 10(1):97-110
Country of Publication:
United States
Language:
English

Citation Formats

Karpinets, Tatiana V., Obraztsova, Anna, Wang, Yanbing, Schmoyer, Denise D., Kora, Guruprasad, Park, Byung H., Serres, Margrethe H., Romine, Margaret F., Land, Miriam L., Kothe, Terence B., Fredrickson, Jim K., Nealson, Kenneth H., and Uberbacher, Edward. Conserved synteny at the protein family level reveals genes underlying Shewanella species cold tolerance and predicts their novel phenotypes. United States: N. p., 2010. Web. doi:10.1007/s10142-009-0142-y.
Karpinets, Tatiana V., Obraztsova, Anna, Wang, Yanbing, Schmoyer, Denise D., Kora, Guruprasad, Park, Byung H., Serres, Margrethe H., Romine, Margaret F., Land, Miriam L., Kothe, Terence B., Fredrickson, Jim K., Nealson, Kenneth H., & Uberbacher, Edward. Conserved synteny at the protein family level reveals genes underlying Shewanella species cold tolerance and predicts their novel phenotypes. United States. doi:10.1007/s10142-009-0142-y.
Karpinets, Tatiana V., Obraztsova, Anna, Wang, Yanbing, Schmoyer, Denise D., Kora, Guruprasad, Park, Byung H., Serres, Margrethe H., Romine, Margaret F., Land, Miriam L., Kothe, Terence B., Fredrickson, Jim K., Nealson, Kenneth H., and Uberbacher, Edward. Mon . "Conserved synteny at the protein family level reveals genes underlying Shewanella species cold tolerance and predicts their novel phenotypes". United States. doi:10.1007/s10142-009-0142-y.
@article{osti_974921,
title = {Conserved synteny at the protein family level reveals genes underlying Shewanella species cold tolerance and predicts their novel phenotypes},
author = {Karpinets, Tatiana V. and Obraztsova, Anna and Wang, Yanbing and Schmoyer, Denise D. and Kora, Guruprasad and Park, Byung H. and Serres, Margrethe H. and Romine, Margaret F. and Land, Miriam L. and Kothe, Terence B. and Fredrickson, Jim K. and Nealson, Kenneth H. and Uberbacher, Edward},
abstractNote = {Bacteria of the genus Shewanella can thrive in different environments and demonstrate significant variability in their metabolic and ecophysiological capabilities including cold and salt tolerance. Genomic characteristics underlying this variability across species are largely unknown. In this study we address the problem by a comparison of the physiological, metabolic and genomic characteristics of 19 sequenced Shewanella species. We have employed two novel approaches based on association of a phenotypic trait with the number of the trait-specific protein families (Pfam domains) and on the conservation of synteny (order in the genome) of the trait-related genes. Our first approach is top-down and involves experimental evaluation and quantification of the species’ cold tolerance followed by identification of the correlated Pfam domains and genes with a conserved synteny. The second, a bottom-up approach, predicts novel phenotypes of the species by calculating profiles of each Pfam domain among their genomes and following pair-wise correlation of the profiles and their network clustering. Using the first approach we find a link between cold and salt tolerance of the species and the presence in the genome of a Na+/H+ antiporter gene cluster. Other cold tolerance related genes includes peptidases, chemotaxis sensory transducer proteins, a cysteine exporter, and helicases. Using the bottom-up approach we found several novel phenotypes in the newly sequenced Shewanella species, including degradation of aromatic compounds by an aerobic hybrid pathway in S. woodyi, degradation of ethanolamine by S. benthica, and propanediol degradation by S. putrefaciens CN32 and S. sp. W3-18-1.},
doi = {10.1007/s10142-009-0142-y},
journal = {Functional & Integrative Genomics, 10(1):97-110},
number = ,
volume = ,
place = {United States},
year = {Mon Mar 01 00:00:00 EST 2010},
month = {Mon Mar 01 00:00:00 EST 2010}
}
  • In spite of a rapid growth in the number of sequenced bacteria and significant progress in the annotation of their genomes, current computational technologies are limited in their capability to associate the genotype of a sequenced bacterial organism with its phenotypic traits. We evaluated two novel, complimentary approaches that can facilitate this task. They are based on correlation between the numbers of the trait-specific protein families or Pfam domains and a quantitative characteristic of the phenotypic trait among different bacterial species. Our first, a top-down approach, involves quantification and comparison of a higher-level characteristic, a bacterial phenotype, to reveal genomicmore » characteristics and specific genes related to the phenotype. The second, a bottom-up approach, predicts phenotypes by quantification of molecular functions in the genomes of closely related bacterial species and by following pair-wise correlation of the molecular functions enrichments and their network clustering. The approach is implemented using network analysis tools. The approaches were validated by a comparison of 19 sequenced Shewanella species. Using the first approach, we were able to identify specific domains and gene clusters associated with cold tolerance of these mesophilic species and to predict some novel cellular mechanisms underlying the phenotype. We find that in three tested species both cold and salt tolerance relate to presence in their genome of a specific Na+/H+ antiporter. By using the second approach we identified genomic clusters predicting several environmentally relevant phenotypes in the newly sequenced Shewanella species including degradation of aromatic compounds by an aerobic hybrid pathway, utilization of ethanolamine, and arsenic and copper resistance. Results of the study confirm validity of the approaches and their utility for (i) computational predictions of phenotypic traits in the sequenced organisms, (ii) revealing genomic determinants of known complex phenotypes, (iii) orthologs prediction, and for (iv) discovery of function of unknown domains and hypothetical proteins.« less
  • The pyridine nucleotide cycle (PNC) is a network of salvage and recycling routes maintaining homeostasis of NAD(P) cofactor pool in the cell. Nicotinamide mononucleotide (NMN) deamidase (EC 3.5.1.42), one of the key enzymes of the bacterial PNC was originally described in Enterobacteria, but the corresponding gene eluded identification for over 30 years. A genomics-based reconstruction of NAD metabolism across hundreds bacterial species suggested that NMN deamidase reaction is the only possible way of nicotinamide salvage in the marine bacterium Shewanella oneidensis. This prediction was verified via purification of native NMN deamidase from S. oneidensis followed by the identification of themore » respective gene, termed pncC. Enzymatic characterization of the PncC protein, as well as phenotype analysis of deletion mutants, confirmed its proposed biochemical and physiological function in S. oneidensis. Of the three PncC homologs present in E. coli, NMN deamidase activity was confirmed only for the recombinant purified product of the ygaD gene. A comparative analysis at the level of sequence and three dimensional structure, which is available for one of the PncC family member, shows no homology with any previously described amidohydrolases. Multiple alignment analysis of functional and non functional PncC homologs, together with NMN docking experiments, allowed us to tentatively identify the active site area and conserved residues therein. An observed broad phylogenomic distribution of predicted functional PncCs in bacterial kingdom is consistent with a possible role in detoxification of NMN, resulting from NAD utilization by DNA ligase.« less
  • The human serotonin (5-hydroxytryptamine, 5-HT) transporter (hSERT, SLC6A4) figures prominently in the etiology or treatment of many prevalent neurobehavioral disorders including anxiety, alcoholism, depression, autism and obsessive-compulsive disorder (OCD). Here we utilize naturally occurring polymorphisms in recombinant inbred (RI) lines to identify novel phenotypes associated with altered SERT function. The widely used mouse strain C57BL/6J, harbors a SERT haplotype defined by two nonsynonymous coding variants (Gly39 and Lys152 (GK)). At these positions, many other mouse lines, including DBA/2J, encode Glu39 and Arg152 (ER haplotype), assignments found also in hSERT. Synaptosomal 5-HT transport studies revealed reduced uptake associated with the GKmore » variant. Heterologous expression studies confirmed a reduced SERT turnover rate for the GK variant. Experimental and in silico approaches using RI lines (C57Bl/6J X DBA/2J=BXD) identifies multiple anatomical, biochemical and behavioral phenotypes specifically impacted by GK/ER variation. Among our findings are multiple traits associated with anxiety and alcohol consumption, as well as of the control of dopamine (DA) signaling. Further bioinformatic analysis of BXD phenotypes, combined with biochemical evaluation of SERT knockout mice, nominates SERT-dependent 5-HT signaling as a major determinant of midbrain iron homeostasis that, in turn, dictates ironregulated DA phenotypes. Our studies provide a novel example of the power of coordinated in vitro, in vivo and in silico approaches using murine RI lines to elucidate and quantify the system-level impact of gene variation.« less
  • The life cycle of the protozoan parasite Trypanosoma cruzi comprises rounds of proliferative cycles and differentiation in distinct host environments. Ras GTPases are molecular switches that play pivotal regulatory functions in cell fate. Rjl is a novel GTPase with unknown function. Herein we show that TcRjl blocks in vivo cell differentiation. The forced expression of TcRjl leads to changes in the overall tyrosine protein phosphorylation profile of parasites. TcRjl expressing parasites sustained DNA synthesis regardless the external stimuli for differentiation. Heterologous expression in the Drosophila melanogaster genetic system strongly suggests a role from TcRjl protein in RTK-dependent pathways and MAPK activation.
  • A conserved cluster of chemotaxis genes was identified from the genome sequences of fifteen Shewanella species. An in-frame deletion of the cheA-3 gene, which is located in this cluster, was created in S. oneidensis MR-1 and the gene shown to be essential for chemotactic responses to anaerobic electron acceptors. The CheA-3 protein showed strong similarity to Vibrio cholerae CheA-2 and P. aeruginosa CheA-1, two proteins that are also essential for chemotaxis. The genes encoding these proteins were shown to be located in chemotaxis gene clusters closely related to the cheA-3-containing cluster in Shewanella species. The results of this study suggestmore » that a combination of gene neighborhood and homology analyses may be used to predict which cheA genes are essential for chemotaxis in groups of closely related microorganisms.« less