Dataset Information

New, closely related haloarchaeal viral elements with different nucleic Acid types.

ABSTRACT: During the search for haloarchaeal viruses, we isolated and characterized a new pleomorphic lipid-containing virus, Haloarcula hispanica pleomorphic virus 1 (HHPV-1), that infects the halophilic archaeon Haloarcula hispanica. The virus contains a circular double-stranded DNA genome of 8,082 bp in size. The organization of the genome shows remarkable synteny and amino acid sequence similarity to the genome and predicted proteins of the halovirus HRPV-1, a pleomorphic single-stranded DNA virus that infects a halophilic archaeon Halorubrum sp. Analysis of the two halovirus sequences, as well as the entire nucleotide sequence of the 10.8-kb pHK2-plasmid and a 12.6-kb chromosomal region in Haloferax volcanii, allows us to suggest a new group of closely related viruses with genomes of either single-stranded or double-stranded DNA. Currently, closely related viruses are considered to have the same genome type. Our observation clearly contradicts this categorization and indicates that we should reconsider the way we classify viruses. Our results also provide a new example of related viruses where the viral structural proteins have not diverged as much as the proteins associated with genome replication. This result further strengthens the proposal for higher-order classification to be based on virion architecture rather than on genome type or replication mechanism.

SUBMITTER: Roine E

PROVIDER: S-EPMC2838124 | biostudies-literature | 2010 Apr

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

New, closely related haloarchaeal viral elements with different nucleic Acid types.

Roine Elina E Kukkaro Petra P Paulin Lars L Laurinavicius Simonas S Domanska Ausra A Somerharju Pentti P Bamford Dennis H DH

Journal of virology 20100120 7

During the search for haloarchaeal viruses, we isolated and characterized a new pleomorphic lipid-containing virus, Haloarcula hispanica pleomorphic virus 1 (HHPV-1), that infects the halophilic archaeon Haloarcula hispanica. The virus contains a circular double-stranded DNA genome of 8,082 bp in size. The organization of the genome shows remarkable synteny and amino acid sequence similarity to the genome and predicted proteins of the halovirus HRPV-1, a pleomorphic single-stranded DNA virus tha ...[more]

PMID: 20089654

Similar Datasets

Project description:BACKGROUND: Two closely related ICEs, ICESt1 and ICESt3, have been identified in the lactic acid bacterium Streptococcus thermophilus. While their conjugation and recombination modules are almost identical (95% nucleotide identity) and their regulation modules related, previous work has demonstrated that transconjugants carrying ICESt3 were generated at rate exceeding by a 1000 factor that of ICESt1. RESULTS: The functional regulation of ICESt1 and ICESt3 transcription, excision and replication were investigated under different conditions (exponential growth or stationary phase, DNA damage by exposition to mitomycin C). Analysis revealed an identical transcriptional organization of their recombination and conjugation modules (long unique transcript) whereas the transcriptional organization of their regulation modules were found to be different (two operons in ICESt1 but only one in ICESt3) and to depend on the conditions (promoter specific of stationary phase in ICESt3). For both elements, stationary phase and DNA damage lead to the rise of transcript levels of the conjugation-recombination and regulation modules. Whatever the growth culture conditions, excision of ICESt1 was found to be lower than that of ICESt3, which is consistent with weaker transfer frequencies. Furthermore, for both elements, excision increases in stationary phase (8.9-fold for ICESt1 and 1.31-fold for ICESt3) and is strongly enhanced by DNA damage (38-fold for ICESt1 and 18-fold for ICESt3). Although ICEs are generally not described as replicative elements, the copy number of ICESt3 exhibited a sharp increase (9.6-fold) after mitomycin C exposure of its harboring strain CNRZ385. This result was not observed when ICESt3 was introduced in a strain deriving ICESt1 host strain CNRZ368, deleted for this element. This finding suggests an impact of the host cell on ICE behavior. CONCLUSIONS: All together, these results suggest a novel mechanism of regulation shared by ICESt1, ICESt3 and closely related ICEs, which we identified by analysis of recently sequenced genomes of firmicutes. This is the first report of a partial shutdown of the activity of an ICE executed by a strain belonging to its primary host species. The sharp increase of ICESt3 copy number suggests an induction of replication; such conditional intracellular replication may be common among ICEs.

Dataset Information

New, closely related haloarchaeal viral elements with different nucleic Acid types.

Publications

New, closely related haloarchaeal viral elements with different nucleic Acid types.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets