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Descriptions are generated automatically from the ICTVdB database including links. Some descriptions are only very basic and links may point to documents that are not yet published on the Web.

00.073.0.01. Alphavirus

Cite this publication as: ICTVdB Management (2006). 00.073.0.01. Alphavirus. In: ICTVdB - The Universal Virus Database, version 4. Büchen-Osmond, C. (Ed), Columbia University, New York, USA

Cite this site as: ICTVdB - The Universal Virus Database, version 4. http://www.ncbi.nlm.nih.gov/ICTVdb/ICTVdB/

Table of Contents

Classification

This is a description of an invertebrate or vertebrate virus at the genus level.

ICTVdB Virus Code: 00.073.0.01. Virus accession number: 073001GE. Obsolete virus code: 73.0.1.; superceded accession number: 73010000.
NCBI Taxon Identifier NCBI Taxonomy ID: 11019.

Name, Synonyms and Lineage

Synonym(s): Arbovirus group A. Virus is of the family 00.073. Togaviridae.

Virion Properties

Morphology

Virions consist of an envelope and a nucleocapsid. During their life cycle, virions have not been observed outside a cellular environment and have a cell-associated cycle. Virus capsid is tightly enveloped by a detergent sensitive lipoprotein. Virions are spherical to pleomorphic. Virions measure 70 nm in diameter. Surface projections are distinctive glycoprotein spikes composed of two virus proteins forming heterodimers covering evenly the surface. Capsid/nucleocapsid is round and exhibits icosahedral symmetry (T=4). The nucleocapsid is isometric and has a diameter of 40 nm. Capsids appear round.
































Diagrams of Semliki Forest virus are from the Fuller Group.

Physicochemical and Physical Properties

The molecular mass (Mr) of virions is 52 x 106. Virions have a buoyant density in sucrose of 1.18-1.19 g cm-3, or 1.22 g cm-3. The sedimentation coefficient is 280 S20w. The thermal inactivation point (TIP) is at 58°C. The longevity in vitro (LIV) is 0.35 days (at 37°C in culture medium). Under in vitro conditions virions are stable in alkaline environment of pH 7-8. Virions are sensitive to treatment with organic solvents and detergents (which solubilzes their lipoprotein envelops). The infectivity is reduced after exposure to irradiation.

Nucleic Acid

The genome is not segmented and contains a single molecule of linear positive-sense, single-stranded RNA. The complete genome is 11000-17000 nucleotides long. The RNA. The 5'-end of the genome has a methylated nucleotide cap. The 3'-terminus has a poly (A) tract.

GenBank records for nucleotide sequences; complete genome sequences.

Proteins

The viral genome encodes structural proteins and non-structural proteins. Virions consist of 4 structural protein(s).

Lipids

Lipids are present and located in the envelope. Virions are composed of 30% lipids by weight. The composition of viral lipids and host cell membranes are similar. The lipids are of host origin and are derived from host cell membranes. Viral membranes include phosphatidyl ethanolamine, phosphatidyl choline, phosphatidyl serine, cholesterol, and sphingomyelin.

Genome Organization and Replication

By itself, genomic nucleic acid is infectious.

Antigenicity

Serological relationships between different members are considerable. Homologies can be identified in amino acid sequences of the coat protein of non-vector transmitted viruses (of about 40%). Cross-reactivity is found. Cross-reactivity between species, but not genera. Species that are serologically interrelated have antigenic homologies with different species of the same serogroup or complex. Classification of members of this taxon is based on their antigenic properties (initially).

Biological Properties

Natural Host

Virus infects during its life cycle arthropod and vertebrate hosts. Domain
Viral hosts belong to the Domain Eucarya.

Domain Eucarya
Kingdom Animalia.

Kingdom Animalia
Phylum Arthropoda and Chordata.

Phylum Arthropoda
Subphylum Hexapoda; Class Insecta; Subclass Pterygota (winged insects), Order Diptera.

Phylum Vertebrata
Subphylum Vertebrata.

Class Aves and Mammalia.

Class Mammalia Order Primates;
Family Hominidae.
Virus infects Homo sapiens (human).

Transmission and Vector Relationships

Virus is transmitted by a vector.

Vector Transmission:
Virus is transmitted by arthropods, insects. Virus replicates in the vector.

Histopathology: Virions are found in the cytoplasm.

Geographical Distribution

The virus is probably distributed worldwide.

Taxonomic Structure of the Genus

Type species 00.073.0.01.001. Sindbis virus .

Species in the Genus

List of Species in the Genus.

Data Sources and Contributions

The description has been compiled from data in the ICTV Report presented by Strauss JH, Calisher CH, Dalgarno L, the late Dalrymple JM, Frey TK, Pettersson RF, Rice CM, Spaan WJM.

References

The following generic references are cited in the most recent ICTV Report.

PubMed References. .



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DELTA - DEscription Language for TAxonomy developed by Dr Mike Dallwitz, Toni Paine and Eric Zurcher, CSIRO Entomology, Canberra, Australia. ICTVdB - The Universal Virus Database, developed for the International Committee on Taxonomy of Viruses by Dr Cornelia Büchen-Osmond is written in DELTA. The virus descriptions in ICTVdB are coded by, or using data from experts in the field of virology or members ICTV. The character list is the underlying code. All virus descriptions are based on the character list and natural language translations are automatically generated and formatted for display on the Web from the descriptions in DELTA-format. The description has been generated automatically from DELTA files. DELTA - DEscription Language for TAxonomy developed by Dr Mike Dallwitz, Toni Paine and Eric Zurcher, CSIRO Entomology, Canberra, Australia.

ICTVdB - The Universal Virus Database, developed for the International Committee on Taxonomy of Viruses (ICTV) by Dr Cornelia Büchen-Osmond, is written in DELTA. The virus descriptions in ICTVdB are coded by ICTV members and experts, or by the ICTVdB Management using data provided by the experts, the literature or the latest ICTV Report. The character list is the underlying code. All virus descriptions are based on the character list and natural language translations from the encoded descriptions are automatically generated and formatted for display on the Web.

Developer of the DELTA software: M. J. Dallwitz, T. Paine and E. Zurcher

ICTVdB and DELTA related References

Comments to ICTVdB Management
Last updated on 25 April 2006 by Cornelia Büchen-Osmond
Copyright © 2002    International Committee on Taxonomy of Viruses.    All rights reserved.


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