A prophage-encoded actin-like protein required for efficient viral DNA replication in bacteria
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ABSTRACT:
ORGANISM(S): Escherichia coli Corynebacterium glutamicum Gluconobacter oxydans Bacillus subtilis subsp. subtilis str. 168 Corynebacterium glutamicum ATCC 13032
PROVIDER: GSE45907 | GEO | 2015/05/01
SECONDARY ACCESSION(S): PRJNA196628
REPOSITORIES: GEO
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Project description:In host cells, viral replication is localized at specific subcellular sites. Viruses that infect eukaryotic and prokaryotic cells often use host-derived cytoskeletal structures, such as the actin skeleton, for intracellular positioning. Here, we describe that a prophage, CGP3, integrated into the genome of Corynebacterium glutamicum encodes an actin-like protein, AlpC. Biochemical characterization confirms that AlpC is a bona fide actin-like protein and cell biological analysis shows that AlpC forms filamentous structures upon prophage induction. The co-transcribed adaptor protein, AlpA, binds to a consensus sequence in the upstream promoter region of the alpAC operon and also interacts with AlpC, thus connecting circular phage DNA to the actin-like filaments. Transcriptome analysis revealed that alpA and alpC are among the early induced genes upon excision of the CGP3 prophage. Furthermore, qPCR analysis of mutant strains revealed that both AlpA and AlpC are required for efficient phage replication. Altogether, these data emphasize that AlpAC are crucial for the spatio-temporal organization of efficient viral replication. This is remarkably similar to actin-assisted membrane localization of eukaryotic viruses that use the actin cytoskeleton to concentrate virus particles at the egress sites and provides a link of evolutionary conserved interactions between intracellular virus transport and actin.
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Project description:Active segregation of DNA in bacteria is catalyzed by cytomotive structures. Mediators of subcellular plasmid positioning are Walker-type ATPases (ParA), actin-like proteins, or tubulin homologs. These motor proteins are coupled to the DNA via adaptor proteins that recognize specific DNA motifs. Here, we describe that a temperate phage, CGP3, integrated into the genome of Corynebacterium glutamicum ATCC 13032 encodes an actin-like protein, AlpC. Biochemical characterization confirms that AlpC is a bona fide actin-like protein and cell biological analysis shows that AlpC forms dynamic filamentous structures upon phage induction. The co-transcribed AlpA protein binds to a specific region of the phage DNA, possibly functioning as an adaptor protein that connects circular phage DNA to the tips of the AlpC filaments. The AlpC filaments transport phage DNA to the cell membrane of the host cell. Furthermore, both AlpA and AlpC are required for efficient phage replication. This is remarkably similar to actin-assisted membrane localization of eukaryotic viruses that use the actin cytoskeleton to concentrate virus particles at the egress sites.
2015-05-01 | GSE45906 | GEO
Project description:Active segregation of DNA in bacteria is catalyzed by cytomotive structures. Mediators of subcellular plasmid positioning are Walker-type ATPases (ParA), actin-like proteins, or tubulin homologs. These motor proteins are coupled to the DNA via adaptor proteins that recognize specific DNA motifs. Here, we describe that a temperate phage, CGP3, integrated into the genome of Corynebacterium glutamicum ATCC 13032 encodes an actin-like protein, AlpC. Biochemical characterization confirms that AlpC is a bona fide actin-like protein and cell biological analysis shows that AlpC forms dynamic filamentous structures upon phage induction. The co-transcribed AlpA protein binds to a specific region of the phage DNA, possibly functioning as an adaptor protein that connects circular phage DNA to the tips of the AlpC filaments. The AlpC filaments transport phage DNA to the cell membrane of the host cell. Furthermore, both AlpA and AlpC are required for efficient phage replication. This is remarkably similar to actin-assisted membrane localization of eukaryotic viruses that use the actin cytoskeleton to concentrate virus particles at the egress sites.
2015-05-01 | GSE45905 | GEO
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Project description:The Corynebacterium glutamicum ATCC 13032 prophage CGP3 encodes an actin-like protein, AlpC that was shown to be involved in viral DNA transport and efficient viral DNA replication. AlpC binds to an adapter, AlpA that in turn binds to specific DNA sequences, termed alpS sites. Thus, the AlpAC system is similar to the known plasmid segregation system ParMRS. So far it is unclear how the AlpACS system mediates DNA transport and, whether AlpA and AlpC functionally interact. We show here that AlpA modulates AlpC filamentation dynamics in a dual way. Unbound AlpA stimulates AlpC filament disassembly, while AlpA bound to alpS sites allows for AlpC filament formation. Based on these results we propose a simple search and capture model that explains DNA segregation by viral AlpACS DNA segregation system.
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