TABLE 1.
PRV gene functions
| Gene | Size (kDa) | Common name | Proposed function(s)a | Structural role | Core |
|---|---|---|---|---|---|
| ORF1.2 | 35.3 | Unknown | Virion | No | |
| ORF1 | 21.8 | Unknown | Virion | No | |
| UL54 | 40.4 | ICP27 | Transcription modulation; cell-cell spread; RNA-binding protein | Nonstructural | Yes |
| UL53 | 33.8 | gK | Viral egress (secondary envelopment); glycoprotein K; type III membrane protein; gK/UL20 together inhibit glycoprotein-mediated membrane fusion | Virion (envelope) | No |
| UL52 | 103.3 | DNA replication; primase subunit of UL5/UL8/UL52 complex | Nonstructural | Yes | |
| UL51 | 25 | Viral egress (secondary envelopment); tegument protein, potentially palmytoilated | Virion (tegument) | Yes | |
| UL50 | 28.6 | dUTPase | dUTPase | Nonstructural | Yes |
| UL49.5 | 10.1 | gN | Immune evasion (TAP inhibitor); glycoprotein N; type I membrane protein; complexed with gM | Virion (envelope) | Yes |
| UL49 | 25.9 | VP22 | Interacts with C-terminal domains of gE & gM; tegument protein | Virion (tegument) | No |
| UL48 | 45.1 | VP16, α-TIF | Gene regulation (transactivator); viral egress (secondary envelopment); tegument protein | Virion (tegument) | No |
| UL47 | 80.4 | VP13/14 | Viral egress (secondary envelopment); tegument protein | Virion (tegument) | No |
| UL46 | 75.5 | VP11/12 | Unknown; tegument protein | Virion (tegument) | No |
| UL27 | 100.2 | gB | Viral entry (fusion); cell-cell spread; glycoprotein B; type I membrane protein | Virion (envelope) | Yes |
| UL28 | 78.9 | ICP18.5 | DNA cleavage and packaging; component of the UL15/UL28 terminase | Capsid precursor | Yes |
| UL29 | 125.3 | ICP8 | DNA replication and recombination; binds single stranded DNA | Nonstructural | Yes |
| UL30 | 115.3 | DNA replication; DNA polymerase subunit of UL30/UL42 holoenzyme | Nonstructural | Yes | |
| UL31 | 30.4 | Viral egress (nuclear egress); present only in primary enveloped virion; interacts with UL34 | Primary virion (tegument) | Yes | |
| UL32 | 51.6 | DNA packaging; efficient localization of capsids to replication compartments | Capsid precursor | Yes | |
| UL33 | 12.7 | DNA cleavage and packaging; associates with UL28 and UL15 | Nonstructural | Yes | |
| UL34 | 28.1 | Viral egress (nuclear egress); present only in primary enveloped virion; tail-anchored type II nuclear membrane protein; interacts with UL31 | Primary virion (envelope) | Yes | |
| UL35 | 11.5 | VP26 | Surface capsid protein | Virion (capsid) | Yes |
| UL36 | 324.4 | VP1/2 | Viral egress (capsid tegumentation); large tegument protein; interacts with UL37 and capsid | Virion (tegument) | Yes |
| UL37 | 98.2 | Viral egress (capsid tegumentation); interacts with UL36 | Virion (tegument) | Yes | |
| UL38 | 40 | VP19c | Minor capsid protein; UL38/UL18/UL18 triplex component | Virion (capsid) | Yes |
| UL39 | 91.1 | RR1 | Nucleotide synthesis; large subunit of ribonucleotide reductase | Nonstructural | Yes |
| UL40 | 34.4 | RR2 | Nucleotide synthesis; small subunit of ribonucleotide reductase | Nonstructural | No |
| UL41 | 40.1 | VHS | Gene regulation, RNAse, degrades host and viral mRNAs | Virion (tegument) | No |
| UL42 | 40.3 | DNA replication; polymerase accessory subunit of UL30/UL42 holoenzyme | Nonstructural | Yes | |
| UL43 | 38.1 | Inhibits glycoprotein-mediated membrane fusion; type III membrane protein | Virion (envelope) | No | |
| UL44 | 51.2 | gC | Viral entry (virion attachment); glycoprotein C; type I membrane protein; binds to heparan sulfate | Virion (envelope) | No |
| UL26.5 | 28.2 | pre-VP22a | Major scaffold protein; substrate for UL26 protease; capsid formation and maturation | Capsid precursor | Yes |
| UL26 | 54.6 | VP24 | Minor scaffold protein; capsid maturation protease | Capsid precursor | Yes |
| UL25 | 57.4 | Capsid-associated protein; required for capsid assembly | Virion (capsid) | Yes | |
| UL24 | 19.1 | Unknown; type III membrane protein | ? | Yes | |
| UL23 | 35 | TK | Nucleotide synthesis; thymidine kinase; selectively activates acyclovir | Nonstructural | No |
| UL22 | 71.9 | gH | Viral entry (fusion); cell-cell spread; glycoprotein H; type I membrane protein; complexed with gL | Virion (envelope) | Yes |
| UL21 | 55.2 | Unknown, capsid-associated tegument protein; interacts with UL16 | Virion (tegument) | Yes | |
| UL20 | 16.7 | Viral egress; type III membrane protein; required for gK processing; gK/UL20 together inhibit glycoprotein-mediated membrane fusion | ? | No | |
| UL19 | 146 | VP5 | Major capsid protein; forms hexons and pentons | Virion (capsid) | Yes |
| UL18 | 31.6 | VP23 | Minor capsid protein; UL38/UL18/UL18 triplex component | Virion (capsid) | Yes |
| UL17 | 64.2 | DNA cleavage and encapsidation | Virion (inner capsid) | Yes | |
| UL16 | 34.8 | Unknown; tegument protein; interacts with UL21 | Virion (tegument) | Yes | |
| UL15 | 79.1 | DNA cleavage/encapsidation; terminase subunit of the UL15/UL28 terminase; interacts with UL33, UL28 & UL6 | Capsid precursor | Yes | |
| UL14 | 17.9 | Unknown | ? | Yes | |
| UL13 | 41.1 | VP18.8 | Unknown; protein-serine/threonine kinase | Virion (tegument) | Yes |
| UL12 | 51.3 | AN | DNA recombination; alkaline exonuclease | ? | Yes |
| UL11 | 7 | Viral egress (secondary envelopment); membrane-associated tegument protein | Virion (tegument) | Yes | |
| UL10 | 41.5 | gM | Inhibits glycoprotein-mediated membrane fusion; glycoprotein M; type III membrane protein; C terminus interacts with tegument protein UL49; complexed with gN | Virion (envelope) | Yes |
| UL9 | 90.5 | OBP | Sequence-specific ori-binding protein, ATP-dependent helicase motif | Nonstructural | No |
| UL8.5 | 51 | OPBC | C-terminal domain of UL9 | ? | No |
| UL8 | 71.2 | DNA replication; part of UL5/UL8/UL52 helicase/primase complex | Nonstructural | Yes | |
| UL7 | 29 | Unknown | ? | Yes | |
| UL6 | 70.3 | Capsid protein; portal protein; docking site for terminase | Virion (capsid) | Yes | |
| UL5 | 92.1 | DNA replication; part of UL5/UL8/UL52 helicase/primase complex; helicase motif | Non-structural | Yes | |
| UL4 | 15.8 | Unknown | ? | No | |
| UL3.5 | 24 | Viral egress (secondary envelopment); membrane-associated protein | ? | No | |
| UL3 | 25.6 | Unknown | Nonstructural | No | |
| UL2 | 33 | UNG | DNA repair; Uracil-DNA glycosylase | Nonstructural | Yes |
| UL1 | 16.5 | gL | Viral entry (fusion); cell-cell spread; glycoprotein L; membrane anchored via complex with gH | Virion (envelope) | Yes |
| EP0 | 43.8 | ICP0 | Gene regulation (transactivator); early protein; ND10 structure modulation; contains RING finger motif | Virion | No |
| IE180 | 148.6 | ICP4 | Gene regulation (transactivator); immediate-early protein | Nonstructural | No |
| US1 | 39.6 | RSp40/ICP22 | Unknown; HSV-1 homolog (ICP22) acts as regulator of gene expression | ? | No |
| US3 (minor) | 42.9 | PK | Minor form of protein kinase (53-kDa mobility); inhibits apoptosis; mitochondrial targeting motif | ? | No |
| US3 (major) | 36.9 | PK | Viral egress (nuclear egress); inhibits apoptosis; major form of protein kinase (41-kDa mobility); found in both primary and secondary enveloped virions | Virion (tegument) | No |
| US4 | 53.7 | gG | Unknown; glycoprotein G (secreted) | Secreted | No |
| US6 | 44.3 | gD | Viral entry (cellular receptor binding protein); glycoprotein D; type I membrane protein | Virion (envelope) | No |
| US7 | 38.7 | gI | Cell-cell spread; glycoprotein I; type I membrane protein; complexed with gE | Virion (envelope) | No |
| US8 | 62.4 | gE | Cell-cell spread; glycoprotein E; type I membrane protein; complexed with gI; C-terminus interacts with UL49; protein sorting in axons | Virion (envelope) | No |
| US9 | 11.3 | 11K | Protein sorting in axons; type II tail-anchored membrane protein | Virion (envelope) | No |
| US2 | 27.7 | 28K | Tegument protein; membrane associated protein | Virion (tegument) | No |
a
Gene functions in italics rely primarily on studies of the HSV-1 homolog.