Erythrovirus is a genus of viruses in the family Parvoviridae

Parvoviridae

The Parvoviridae family includes the smallest known viruses, and some of the most environmentally resistant. They were discovered during the 1960s and affect vertebrates and insects...

.

The type species is parvovirus B19.

Virology

Erythroviruses are small (diameter 18-26 nanometers), non-enveloped icosahedral viruses. The capsid has a T = 1 symmetry and consists of 60 copies of coat protein.

The viral capsid binds to a receptor known as the P antigen, a globoside which is present not only on erythroblasts but also on megakaryocyte

Megakaryocyte

The megakaryocyte is a bone marrow cell responsible for the production of blood thrombocytes , which are necessary for normal blood clotting...

s, endothelial cells, synovium

Synovium

Synovial membrane is the soft tissue found between the articular capsule and the joint cavity of synovial joints....

, trophoblast

Trophoblast

Trophoblasts are cells forming the outer layer of a blastocyst, which provide nutrients to the embryo and develop into a large part of the placenta. They are formed during the first stage of pregnancy and are the first cells to differentiate from the fertilized egg...

, fetal liver

Liver

The liver is a vital organ present in vertebrates and some other animals. It has a wide range of functions, including detoxification, protein synthesis, and production of biochemicals necessary for digestion...

 and heart muscle. Replication is limited to erythroblasts: the reason for this tissue trophism remains unclear.

The genome is a linear, single-stranded DNA 4-6 kilobases in length with terminal hairpin structures at both ends. It is replicated through a unique rolling hairpin mechanism.

The genome encodes three major proteins VP1 and VP2, the viral capsid proteins, and NS1. VP1 and 2 are derived from overlapping reading frames and share substantial amino acid sequences. NS1 is involved in viral replication and the activation of viral gene transcription. It has DNA binding, ATPase

ATPase

ATPases are a class of enzymes that catalyze the decomposition of adenosine triphosphate into adenosine diphosphate and a free phosphate ion. This dephosphorylation reaction releases energy, which the enzyme harnesses to drive other chemical reactions that would not otherwise occur...

, helicase

Helicase

Helicases are a class of enzymes vital to all living organisms. They are motor proteins that move directionally along a nucleic acid phosphodiester backbone, separating two annealed nucleic acid strands using energy derived from ATP hydrolysis.-Function:Many cellular processes Helicases are a...

 and nuclease

Nuclease

A nuclease is an enzyme capable of cleaving the phosphodiester bonds between the nucleotide subunits of nucleic acids. Older publications may use terms such as "polynucleotidase" or "nucleodepolymerase"....

 activity.

Taxonomy

As well as the four recognised species in this genus there also two tentative members;

Bovine parvovirus type 3

Chipmunk parvovirus


The species Chimpmunk parvovirus currently placed in the Erythovirus genus probably belongs in a separate genus.