A novel class of herpesvirus with bivalve hosts.
Ostreid herpesvirus 1 (OsHV-1) is the only member of the Herpesviridae that has an invertebrate host and is associated with sporadic mortality in the Pacific oyster (Crassostrea gigas) and other bivalve species. Cryo-electron microscopy of purified capsids revealed the distinctive T=16 icosahedral structure characteristic of herpesviruses, although the preparations examined lacked pentons. The gross genome organization of OsHV-1 was similar to that of certain mammalian herpesviruses (including herpes simplex virus and human cytomegalovirus), consisting of two invertible unique regions (U(L), 167.8 kbp; U(S), 3.4 kbp) each flanked by inverted repeats (TR(L)/IR(L), 7.6 kbp; TR(S)/IR(S), 9.8 kbp), with an additional unique sequence (X, 1.5 kbp) between IR(L) and IR(S). Of the 124 unique genes predicted from the 207 439 bp genome sequence, 38 were members of 12 families of related genes and encoded products related to helicases, inhibitors of apoptosis, deoxyuridine triphosphatase and RING-finger proteins, in addition to membrane-associated proteins. Eight genes in three of the families appeared to be fragmented. Other genes that did not belong to the families were predicted to encode DNA polymerase, the two subunits of ribonucleotide reductase, a helicase, a primase, the ATPase subunit of terminase, a RecB-like protein, additional RING-like proteins, an ion channel and several other membrane-associated proteins. Sequence comparisons showed that OsHV-1 is at best tenuously related to the two classes of vertebrate herpesviruses (those associated with mammals, birds and reptiles, and those associated with bony fish and amphibians). OsHV-1 thus represents a third major class of the herpesviruses.
Davison
Andrew J
AJ
MRC Virology Unit, Institute of Virology, Church Street, Glasgow G11 5JR, UK.
Trus
Benes L
BL
Laboratory of Structural Biology, National Institute of Arthritis, Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD 20892, USA.|Imaging Sciences Laboratory, Center for Information Technology, National Institutes of Health, Bethesda, MD 20892, USA.
Cheng
Naiqian
N
Laboratory of Structural Biology, National Institute of Arthritis, Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
Steven
Alasdair C
AC
Laboratory of Structural Biology, National Institute of Arthritis, Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
Watson
Moira S
MS
MRC Virology Unit, Institute of Virology, Church Street, Glasgow G11 5JR, UK.
Cunningham
Charles
C
MRC Virology Unit, Institute of Virology, Church Street, Glasgow G11 5JR, UK.
Deuff
Rose-Marie Le
RL
Laboratoire de Génétique et Pathologie, IFREMER, 17390 La Tremblade, France.
Renault
Tristan
T
Laboratoire de Génétique et Pathologie, IFREMER, 17390 La Tremblade, France.
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002213:Capsid / Q000737:chemistry; D004265:DNA Helicases / Q000235:genetics; D016679:Genome, Viral; D006564:Herpesviridae / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D051034:Inhibitor of Apoptosis Proteins; D007814:Larva / Q000821:virology; D008565:Membrane Proteins / Q000235:genetics; D008969:Molecular Sequence Data; D010125:Ostreidae / Q000821:virology*; D011506:Proteins / Q000235:genetics; D011755:Pyrophosphatases / Q000235:genetics; D016415:Sequence Alignment
D051034:Inhibitor of Apoptosis Proteins; D008565:Membrane Proteins; D011506:Proteins; D011755:Pyrophosphatases; C020020:dUTP pyrophosphatase; D004265:DNA Helicases