Tectiviridaeis a family ofviruseswith 10 species in five genera. Bacteria serve as natural hosts.[2][3]Tectiviruses have no head-tail structure, but are capable of producing tail-like tubes of ~ 60×10 nm upon adsorption or afterchloroformtreatment. The name is derived fromLatintectus(meaning 'covered').[4]
| Tectiviridae | |
|---|---|
| |
| CryoEMmodel of Enterobacteria phage PRD1 capsid. PDB entry1gw7[1] | |
Virus classification
| |
| (unranked): | Virus |
| Realm: | Varidnaviria |
| Kingdom: | Bamfordvirae |
| Phylum: | Preplasmiviricota |
| Class: | Tectiliviricetes |
| Order: | Kalamavirales |
| Family: | Tectiviridae |
| Genera | |
Virology
edit
ThevirionsofTectiviridaespecies are non-enveloped, icosahedral and display a pseudo T=25 symmetry.[2]Thecapsidhas two layers. The outer layer is a protein structure of 240 capsid proteins trimers, and the inner one is a proteinaceous lipid membrane which envelopes the virusgenome.Apical spikes extending about 20nanometers(nm) protrude from the icosahedrons vertices.[citation needed]
The genome is a single molecule of linear double-strandedDNAof 15 kilobasesin length, and has 30 open reading frames.[2]It forms a tightly packed coil and encodes several structural proteins. It encodes about 30 proteins that are transcribed in operons. At least 9 structural proteins are present in the viron. The genome is about 66 megadaltonsin weight and constitutes 14–15% of the virion by weight.Lipidsconstitute a further 15% by weight.Carbohydratesare not present.[citation needed]
Life cycle
editViral replication is cytoplasmic. Entry into the host cell is achieved by adsorption into the host cell.[2]After adsorption to the host cell surface the virion extrudes a tail-tube structure through a vertex for genome delivery into the host. Replication follows the DNA strand displacement model. DNA-templated transcription is the method of transcription.[2]Capsid proteins polymerize around a lipoprotein vesicle translocated in the cytoplasm by virion assembly factors.
Mature virons are released by lysis, which, in the case of PRD1, is achieved with the aid of virus-encoded lysis machinery consisting of four proteins: P15 (endolysin),[5]P35 (holin),[6]P36 and P37 (homologues of the Rz/Rz1 proteins of phage lambda).[7]
Taxonomy
editTectiviridaecontains the following genera and species:[3]
Other unassigned phages:[8]
References
edit- ^San Martín C, Huiskonen JT, Bamford JK, Butcher SJ, Fuller SD, Bamford DH, Burnett RM (2002). "Minor proteins, mobile arms and membrane-capsid interactions in the bacteriophage PRD1 capsid".Nature Structural Biology.9(10): 756–63.doi:10.1038/nsb837.PMID12219080.S2CID32856328.
- ^abcde"Viral Zone".ExPASy.Retrieved15 June2015.
- ^ab"Virus Taxonomy: 2020 Release".International Committee on Taxonomy of Viruses (ICTV). March 2021.Retrieved22 May2021.
- ^"ICTV Ninth Report; 2009 Taxonomy Release:Tectiviridae".ICTV.Archived fromthe originalon 24 April 2019.Retrieved18 September2020.
- ^Caldentey J, Hänninen AL, Bamford DH (1994)."Gene XV of bacteriophage PRD1 encodes a lytic enzyme with muramidase activity".Eur J Biochem.225(1): 341–346.doi:10.1111/j.1432-1033.1994.00341.x.PMID7925454.
- ^Rydman PS, Bamford DH (2003)."Identification and mutational analysis of bacteriophage PRD1 holin protein P35".J Bacteriol.185(13): 3795–3803.doi:10.1128/JB.185.13.3795-3803.2003.PMC161566.PMID12813073.
- ^Krupovic M, Cvirkaite-Krupovic V, Bamford DH (2008)."Identification and functional analysis of the Rz/Rz1-like accessory lysis genes in the membrane-containing bacteriophage PRD1".Mol Microbiol.68(2): 492–503.doi:10.1111/j.1365-2958.2008.06165.x.PMID18366440.
- ^Unclassified Tectiviridae.NCBI Taxonomy.
Further reading
edit- ICTVdB—The Universal Virus DatabaseICTVdB Management (2006). 00.068. Tectiviridae. In: ICTVdB—The Universal Virus Database, version 3. Büchen-Osmond, C. (Ed), Columbia University, New York, USA
- Virus Taxonomy:Eighth Report of the International Committee on Taxonomy of Viruses H.V. Van Regenmortel, D.H.L. Bishop, M. H. Van Regenmortel, Claude M. Fauquet (Eds)
- 68.0.1. TectivirusArchived28 September 2007 at theWayback Machine