Virion
A virion (plural, viria or virions) is an inert
While the terms "virus" and "virion" are occasionally confused, recently "virion" is used solely to describe the virus structure outside of cells,[3] while the terms "virus/viral" are broader and also include biological properties such as the infectivity of a virion.[4]
Components
A virion consists of one or more
Capsid
In the vast majority of viruses, the DNA and RNA components are packed into a
).If the genome consists of several segments, these are usually packaged together in a capsid (e.g.,
Since the genome of viruses is relatively simple, the capsid architecture relies on repetition of simple structures, similar to the
In many viruses, the virions have icosahedral symmetry, which can be ideally isometric or elongated. Many virions also have other shapes:
- Inoviridae and Filoviridae: thread-like/filamentous/helical
- Ampullaviridae: bottle-shaped
- Bicaudaviridae, Fuselloviridae, Halspiviridae and Thaspiviridae: spindle- to lemon-shaped
- Poxviridae and Ovaliviridae: ovoid to ellipsoid
- pleomorphic).
From observations using microscopy, there are indications of many more distinct shapes.
Tail
In some groups of viruses—such as the class Caudoviricetes ("tail viruses") and the genus Tupanvirus—the capsid carries an appendage called the "tail".
The tail of the Caudoviricetes is usually divided into:
- a neck, possibly with collar a long, possibly contractile tail sheath
- base plate
- possibly tail fibers/tail spikes
The latter are used to establish contact with the host cell. The tail of these viruses serves as an injection device to introduce their own genome into the host cell.[6] The Caudoviricetes tail material is also differentiated into major and minor tail proteins (MTP and mTP), as seen in the Enterobacteria phage lambda.[7] In addition, there may be a tail spike protein (TSP)[8] or tail fiber protein (TFP).
Even in viruses with helical
Spikes
Spikes (peplomers) can protrude from the capsid, as in the
In viruses of the genus
Viral envelope
In many
References
- ^ Reynolds & Theodore 2023, pp. 20, 24.
- ^ a b Reynolds & Theodore 2023, p. 20.
- ^ a b Reynolds & Theodore 2023, p. 24.
- ^
Hof, Herbert; Dörries, Rüdiger (2005). Bob, Alexander; Bob, Konstantin (eds.). Medical Microbiology (3rd ed.). Stuttgart: Thieme. p. 135. ISBN 3-13-125313-4.
- ^ a b c N. J. Dimmock, Andrew J. Easton, Keith Leppard: Introduction to Modern Virology. 6th edition, Wiley & Blackwell, Malden 2007, ISBN 978-1-4051-3645-7, p. 49, Chapter 4: Classification of Viruses..
- ^ Audrey Leprince, Jacques Mahillon: Phage Adsorption to Gram-Positive Bacteria. In: MDPI: Viruses. Volume 15, No. 1, October 29, 2022, p. 196, doi:10.3390/v15010196.
- ^ Protein Data Bank in Europe: NMR structure of the gpu tail protein from lambda bacteriophage. On: ebi.ac.uk
- ^ Matthew Dunne, Nikolai S. Prokhorov, Martin J. Loessner, Petr G. Leiman: Reprogramming bacteriophage host range: design principles and strategies for engineering receptor binding proteins. In: Current Opinion in Biotechnology. Volume 68, April 2021, pp. 272–281, doi:10.1016/j.copbio.2021.02.006.
- ^
Laso-Pérez, Rafael; Wu, Fabai; Crémière, Antoine; Speth, Daan R.; Magyar, John S.; Zhao, Kehan; Krupovic, Mart; Orphan, Victoria J. (2023-01-19). "Evolutionary diversification of methanotrophic ANME-1 archaea and their expansive virome". Nature Microbiology. 8 (2): 231–245. PMID 36658397.
- ^ Yu Zhang, Zhongjie Zhu, Yuchan Ma, Zhifeng Fu: Paper-based analytical device integrated with bacteriophage tail fiber protein for bacteria detection and antimicrobial susceptibility test. In: Biosensors and Bioelectronics, volume 239, November 1, 2023, p. 115629; doi:10.1016/j.bios.2023.115629.
- PMID 19158076.
Sources
- Reynolds, M.M.; Theodore, L. (2023). "Basics of Virology". A Guide to Virology for Engineers and Applied Scientists: Epidemiology, Emergency Management, and Optimization. Wiley. pp. 19–32. ISBN 978-1-119-85313-8. Retrieved 2024-11-30.