scholarly journals Comparison of Genome Structures of Vibrios, Bacteria Possessing Two Chromosomes

2002 ◽  
Vol 184 (16) ◽  
pp. 4351-4358 ◽  
Author(s):  
Kenichi Tagomori ◽  
Tetsuya Iida ◽  
Takeshi Honda

ABSTRACT Vibrios are gram-negative γ-proteobacteria which are ubiquitous in marine and estuarine environments. Recently, we demonstrated that some, if not all, Vibrio species have two circular chromosomes. The whole genome sequence of Vibrio cholerae N16961 has been reported. In this study, we constructed a physical and genetic map of the genome of Kanagawa phenomenon-positive Vibrio parahaemolyticus strain KX-V237 and compared it with those of V. parahaemolyticus AQ4673 and V. cholerae N16961. The genome of KX-V237 comprised two circular chromosomes (3.3 and 1.9 Mb), similar to the structure of the AQ4673 genome. The relative positions of the genes on the genomes were well conserved in the two strains, but a large inversion on the large chromosomes, probably symmetric around the replication origin, was suggested. Although the sizes of the large chromosomes of KX-V237 and V. cholerae N16961 were similar, the sizes of the small chromosomes were very different. Unlike N16961, the superintegron of KX-V237 was located on the large chromosome. Comparison of the genetic maps of the chromosomes of KX-V237 and V. cholerae N16961 revealed that most of the open reading frames (ORFs) present on the large chromosome of the V. cholerae strain had homologues on the large chromosome of the V. parahaemolyticus strain and that most of the ORFs on the small chromosome of N16961 were present on the small chromosome of KX-V237. The difference in the orders of the ORFs on the chromosomes of N16961 and KX-V237 implies that numerous and frequent genetic exchanges have occurred intrachromosomally rather than interchromosomally.

2000 ◽  
Vol 68 (10) ◽  
pp. 5742-5748 ◽  
Author(s):  
Kwon-Sam Park ◽  
Tetsuya Iida ◽  
Yoshiharu Yamaichi ◽  
Tomohito Oyagi ◽  
Koichiro Yamamoto ◽  
...  

ABSTRACT We have demonstrated that possession of the gene for thermostable direct hemolysin-related hemolysin (trh) coincides with the presence of the urease gene among clinical Vibrio parahaemolyticus strains and that the location of the two genes are in close proximity on the chromosome. Here, we cloned and sequenced the 15,754-bp DNA region containing the trh gene and the gene cluster for urease production from the chromosome of clinicalV. parahaemolyticus (TH3996). We found 16 open reading frames (ORFs) and a lower G+C content (41%) compared with the total genome of this bacterium (46 to 47%). The ure cluster consisted of eight genes, namely, ureDABCEFG andureR. ureR was located 5.2 kb upstream of the other seven genes in the opposite direction. The genetic organization and sequences of the ure genes resembled those found in Proteus mirabilis. Between ureR and the other uregenes, there were five ORFs, which are homologous with the nickel transport operon (nik) of Escherichia coli. We disrupted each of the ureR, ureC, andnikD genes in TH3996 by homologous recombination and analyzed the phenotype of the mutants. In the presence of urea these mutant strains had dramatically less urease activity than the strain they were derived from. Disruption of ureR,nikD, or ureC, however, had no effect on TRH production. The DNA region containing the trh,nik, and ure genes was found in onlytrh-positive strains and not in Kanagawa phenomenon-positive and environmental V. parahaemolyticusstrains. At the end of the region, an insertion sequence-like element existed. These results suggest that the DNA region was introduced intoV. parahaemolyticus in the past through a mechanism mediated by insertion sequences. This is the first reported case that the genes for an ATP-binding cassette-type nickel transport system, which may play a role in nickel transport through bacterial cytoplasmic membrane, are located adjacent to the ure cluster on the genome of an organism.


2000 ◽  
Vol 44 (7) ◽  
pp. 1809-1817 ◽  
Author(s):  
Wyatt C. Smith ◽  
Longkuan Xiang ◽  
Ben Shen

ABSTRACT The macrotetrolides are a family of cyclic polyethers derived from tetramerization, in a stereospecific fashion, of the enantiomeric nonactic acid (NA) and its homologs. Isotope labeling experiments established that NA is of polyketide origin, and biochemical investigations demonstrated that 2-methyl-6,8-dihydroxynon-2E-enoic acid can be converted into NA by a cell-free preparation from Streptomyces lividans that expresses nonS. These results lead to the hypothesis that macrotetrolide biosynthesis involves a pair of enantiospecific polyketide pathways. In this work, a 55-kb contiguous DNA region was cloned from Streptomyces griseus DSM40695, a 6.3-kb fragment of which was sequenced to reveal five open reading frames, including the previously reported nonR andnonS genes. Inactivation of nonS in vivo completely abolished macrotetrolide production. Complementation of thenonS mutant by the expression of nonS intrans fully restored its macrotetrolide production ability, with a distribution of individual macrotetrolides similar to that for the wild-type producer. In contrast, fermentation of thenonS mutant in the presence of exogenous (±)-NA resulted in the production of nonactin, monactin, and dinactin but not in the production of trinactin and tetranactin. These results prove the direct involvement of nonS in macrotetrolide biosynthesis. The difference in macrotetrolide production between in vivo complementation of the nonS mutant by the plasmid-borne nonSgene and fermentation of the nonS mutant in the presence of exogenously added (±)-NA suggests that NonS catalyzes the formation of (−)-NA and its homologs, supporting the existence of a pair of enantiospecific polyketide pathways for macrotetrolide biosynthesis inS. griseus. The latter should provide a model that can be used to study the mechanism by which polyketide synthase controls stereochemistry during polyketide biosynthesis.


2003 ◽  
Vol 185 (22) ◽  
pp. 6658-6665 ◽  
Author(s):  
Kasumi Takeuchi ◽  
Fumiko Taguchi ◽  
Yoshishige Inagaki ◽  
Kazuhiro Toyoda ◽  
Tomonori Shiraishi ◽  
...  

ABSTRACT The deduced amino acid sequences of the flagellins of Pseudomonas syringae pv. tabaci and P. syringae pv. glycinea are identical; however, their abilities to induce a hypersensitive reaction are clearly different. The reason for the difference seems to depend on the posttranslational modification of the flagellins. To investigate the role of this posttranslational modification in the interactions between plants and bacterial pathogens, we isolated genes that are potentially involved in the posttranslational modification of flagellin in P. syringae pv. glycinea (glycosylation island); then defective mutants with mutations in these genes were generated. There are three open reading frames in the glycosylation island, designated orf1, orf2, and orf3. orf1 and orf2 encode putative glycosyltransferases, and mutants with defects in these open reading frames, Δorf1 and Δorf2, secreted nonglycosylated and slightly glycosylated flagellins, respectively. Inoculation tests performed with these mutants and original nonhost tobacco leaves revealed that Δorf1 and Δorf2 could grow on tobacco leaves and caused symptom-like changes. In contrast, these mutants failed to cause symptoms on original host soybean leaves. These data indicate that putative glycosyltransferases encoded in the flagellin glycosylation island are strongly involved in recognition by plants and could be the specific determinants of compatibility between phytopathogenic bacteria and plant species.


2005 ◽  
Vol 187 (18) ◽  
pp. 6488-6498 ◽  
Author(s):  
Vinita Joardar ◽  
Magdalen Lindeberg ◽  
Robert W. Jackson ◽  
Jeremy Selengut ◽  
Robert Dodson ◽  
...  

ABSTRACT Pseudomonas syringae pv. phaseolicola, a gram-negative bacterial plant pathogen, is the causal agent of halo blight of bean. In this study, we report on the genome sequence of P. syringae pv. phaseolicola isolate 1448A, which encodes 5,353 open reading frames (ORFs) on one circular chromosome (5,928,787 bp) and two plasmids (131,950 bp and 51,711 bp). Comparative analyses with a phylogenetically divergent pathovar, P. syringae pv. tomato DC3000, revealed a strong degree of conservation at the gene and genome levels. In total, 4,133 ORFs were identified as putative orthologs in these two pathovars using a reciprocal best-hit method, with 3,941 ORFs present in conserved, syntenic blocks. Although these two pathovars are highly similar at the physiological level, they have distinct host ranges; 1448A causes disease in beans, and DC3000 is pathogenic on tomato and Arabidopsis. Examination of the complement of ORFs encoding virulence, fitness, and survival factors revealed a substantial, but not complete, overlap between these two pathovars. Another distinguishing feature between the two pathovars is their distinctive sets of transposable elements. With access to a fifth complete pseudomonad genome sequence, we were able to identify 3,567 ORFs that likely comprise the core Pseudomonas genome and 365 ORFs that are P. syringae specific.


2018 ◽  
Vol 81 (7) ◽  
pp. 1117-1125 ◽  
Author(s):  
MENGZHE LI ◽  
YANQIU JIN ◽  
HONG LIN ◽  
JINGXUE WANG ◽  
XIUPING JIANG

ABSTRACT Vibrio parahaemolyticus is an important foodborne pathogen that is generally transmitted via raw or undercooked seafood. Endolysins originating from bacteriophages offer a new way to control bacterial pathogens. The objectives of this study were to sequence a novel lytic V. parahaemolyticus phage VPp1 and determine the antibacterial activities of the recombinant endolysin (LysVPp1) derived from this phage. The complete VPp1 genome contained a double-stranded DNA of 50,431 bp with a total G+C content of 41.35%. The genome was predicted to encode 67 open reading frames (ORFs), which were organized as nucleotide metabolism, replication, structure, packaging, lysis, and some additional functions. Two tRNAs were encoded to carry anticodons UGG and CCA. Among the functional proteins, ORF33 was deduced to encode endolysin, whereas no holin/antiholin or Rz/Rz1 lysis gene equivalents were found in the VPp1 genome. ORF33 was cloned and expressed. The endolysin LysVPp1 could lyse 9 of 12 V. parahaemolyticus strains, showing its relatively broader host spectrum than phage VPp1, which lysed only 3 of 12 V. parahaemolyticus strains. Furthermore, for EDTA-pretreated bacterial cells, the optical density of the LysVPp1 treatment group decreased by 0.4 at 450 nm, compared with less than 0.1 in control groups, demonstrating enhanced hydrolytic properties. These results contribute to the potential for development of novel enzybiotics for controlling V. parahaemolyticus.


2017 ◽  
Vol 5 (15) ◽  
Author(s):  
Madhurababu Kunta ◽  
Zheng Zheng ◽  
Fengnian Wu ◽  
John V. da Graca ◽  
Jong-Won Park ◽  
...  

ABSTRACT We report here the draft genome sequence of “Candidatus Liberibacter asiaticus” strain TX2351, collected from Asian citrus psyllids in south Texas, USA. The TX2351 genome has a size of 1,252,043 bp, a G+C content of 36.5%, 1,184 predicted open reading frames, and 52 RNA genes.


2015 ◽  
Vol 3 (6) ◽  
Author(s):  
F. Wu ◽  
X. Deng ◽  
G. Liang ◽  
J. Huang ◽  
Y. Cen ◽  
...  

The genome of “ Candidatus Profftella armatura” strain YCPA from Diaphorina citri in Guangdong, China, was sequenced. The strain has a chromosome of 457,565 bp, 24.3% G+C content, 364 predicted open reading frames (ORFs), and 38 RNAs, and a plasmid, pYCPA54, of 5,458 bp with 23.9% G+C content and 5 ORFs.


2001 ◽  
Vol 183 (13) ◽  
pp. 3958-3966 ◽  
Author(s):  
David Šmajs ◽  
George M. Weinstock

ABSTRACT A cosmid library of DNA from colicin Js-sensitive enteroinvasiveEscherichia coli (EIEC) strain O164 was made in colicin Js-resistant strain E. coli VCS257, and colicin Js-sensitive clones were identified. Sensitivity to colicin Js was associated with the carriage of a three-gene operon upstream of and partially overlapping senB. The open reading frames were designated cjrABC (for colicin Js receptor), coding for proteins of 291, 258, and 753 amino acids, respectively. Tn7 insertions in any of them led to complete resistance to colicin Js. A near-consensus Fur box was found upstream ofcjrA, suggesting regulation of the cjroperon by iron levels. CjrA protein was homologous to iron-regulatedPseudomonas aeruginosa protein PhuW, whose function is unknown; CjrB was homologous to the TonB protein fromPseudomonas putida; and CjrC was homologous to a putative outer membrane siderophore receptor from Campylobacter jejuni. Cloning experiments showed that the cjrBand cjrC genes are sufficient for colicin Js sensitivity. Uptake of colicin Js into sensitive bacteria was dependent on the ExbB protein but not on the E. coli K-12 TonB and TolA, -B, and -Q proteins. Sensitivity to colicin Js is positively regulated by temperature via the VirB protein and negatively controlled by the iron source through the Fur protein. Among EIEC strains, two types of colicin Js-sensitive phenotypes were identified that differed in sensitivity to colicin Js by 1 order of magnitude. The difference in sensitivity to colicin Js is not due to differences between the sequences of the CjrB and CjrC proteins.


2018 ◽  
Vol 6 (25) ◽  
Author(s):  
W. Cai ◽  
Z. Yan ◽  
J. Rascoe ◽  
M. J. Stulberg

The draft genome sequence of “Candidatus Liberibacter asiaticus” strain TX1712, obtained from a Texas citrus tree, is reported here. Strain TX1712 has a draft genome size of 1,203,333 bp, a G+C content of 36.4%, 1,230 predicted open reading frames, and 41 RNAs and comprises 97.4% of the psy62 reference genome.


2021 ◽  
Author(s):  
Mingming Liu ◽  
Yunxia Ni ◽  
Hui Zhao ◽  
Xintao Liu ◽  
Min Jia ◽  
...  

Abstract One victorivirus was detected in the isolate of Corynespora cassiicola strains 20180909-03, which was named Corynespora cassiicola victorivirus 1 (CcVV1). The whole-genome sequence of the virus was sequenced and identified. The CcVV1 genome is 5140 nt and contains 56.87%GC with two large open reading frames (ORFs) overlapping at the tetranucleotide AUGA. The two ORFs were predicted to encode coat protein (CP) and RNA-dependent RNA polymerase (RdRp) respectively, which were conservative in dsRNA fungal viruses of the family Totiviridae. Conservative domains comparison and phylogenetic analysis of the deduced amino acid sequence of RdRp and CP showed that CcVV1 was a new virus of the Victorivirus genus. As far as we know, it is the first report of a genomic sequence of the genus Victorivirus infecting Corynespora cassiicola.


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