Genome sequence, structural proteins, and capsid organization of the cyanophage Syn5: a 'horned' bacteriophage of marine synechococcus
| Autor: | Jennifer M. Houtz, Graham F. Hatfull, Wah Chiu, Wen Jiang, Roger W. Hendrix, Michael E. Ford, Juan Chang, Welkin H. Pope, Jonathan King, Marisa L. Pedulla, Peter Weigele |
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| Rok vydání: | 2006 |
| Předmět: |
Genetics
Synechococcus viruses Cryoelectron Microscopy Molecular Sequence Data Cyanophage Genome Viral Biology biology.organism_classification Article Bacteriophage Open Reading Frames Capsid Structural Biology GenBank Bacteriophages Capsid Proteins Photosynthetic bacteria ORFS Molecular Biology Genomic organization |
| Zdroj: | Journal of molecular biology. 368(4) |
| ISSN: | 0022-2836 |
| Popis: | Marine Synechococcus spp and marine Prochlorococcus spp are numerically dominant photoautotrophs in the open oceans and contributors to the global carbon cycle. Syn5 is a short-tailed cyanophage isolated from the Sargasso Sea on Synechococcus strain WH8109. Syn5 has been grown in WH8109 to high titer in the laboratory and purified and concentrated retaining infectivity. Genome sequencing and annotation of Syn5 revealed that the linear genome is 46,214bp with a 237bp terminal direct repeat. Sixty-one open reading frames (ORFs) were identified. Based on genomic organization and sequence similarity to known protein sequences within GenBank, Syn5 shares features with T7-like phages. The presence of a putative integrase suggests access to a temperate life-cycle. Assignment of eleven ORFs to structural proteins found within the phage virion was confirmed by mass-spectrometry and N-terminal sequencing. Eight of these identified structural proteins exhibited amino acid sequence similarity to enteric phage proteins. The remaining three virion proteins did not resemble any known phage sequences in GenBank as of August 2006. Cryoelectron micrographs of purified Syn5 virions revealed that the capsid has a single “horn”, a novel fibrous structure protruding from the opposing end of the capsid from the tail of the virion. The tail appendage displayed an apparent three-fold rather than six-fold symmetry. An 18Å-resolution icosahedral reconstruction of the capsid revealed a T=7 lattice, but with an unusual pattern of surface knobs. This phage/host system should allow detailed investigation of the physiology and biochemistry of phage propagation in marine photosynthetic bacteria. |
| Databáze: | OpenAIRE |
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