Enveloped, spherical to pleomorphic, 120-200 nm in diameter, T=16 icosahedral symmetry. Capsid consists of 162 capsomers and is surrounded by an amorphous tegument. Glycoproteins complexes are embeded in the lipid envelope.


Monopartite, linear, dsDNA genome of about 150 kb. The genome contains terminal and internal reiterated sequences. The genome sequence is repeated at one end. Each virion contains multiple isomeric forms of the genome


Each viral transcript usually encodes a single protein and has a promoter/regulatory sequence, a TATA box, a transcription initiation site, a 5' leader sequence of 30-300 bp (not translated), a 3' nontranslated sequence of 10-30 bp, and a poly A signal. There are many gene overlaps. There are only few spliced genes. Some of the expressed ORFs are antisense to each other. Some ORFs can be accessed from more than one promoter. There are some non-coding genes.

There are three types of genes: immediate-early, early and late. The immediate-early genes are transcribed immediately after infection and ensure the transcription of early genes, which encode the proteins necessary for the viral replication. The late genes mostly encode structural proteins. Standing apart are genes expressed during latency.

The viral proteins VHS and ICP27 are involved in shut-off of host protein translation in order to ensure the selective expression of viral proteins versus cellular proteins.



Lytic replication:

  1. Attachment of the viral gB, gC, gD and gH proteins to host receptors mediates endocytosis of the virus into the host cell.
  2. Fusion with the plasma membrane to release the core and the tegument proteins into the host cytoplasm.
  3. The capsid is transported to the nuclear pore where the viral DNA is released into the nucleus.
  4. Transcription of immediate early genes which promote transcription of early genes and protect the virus against innate host immunity.
  5. Transcription of early viral mRNA by host polymerase II, encoding proteins involved in replication of the viral DNA.
  6. A first round of circular genome amplification occurs by bidirectional replication
  7. Synthesis of linear concatemer copies of viral DNA by rolling circle.
  8. Transcription of late mRNAs by host polymerase II, encoding structural proteins.
  9. Assembly of the virus in nuclear viral factories and budding through the inner lamella of the nuclear membrane which has been modified by the insertion of herpes glycoproteins, throughout the Golgi and final release at the plasma membrane.

Latent replication : replication of circular viral episome in tandem with the host cell DNA using the host cell replication machinery.

Host-virus interaction

Cell-cycle modulation

The conserved UL24 family of human alpha, beta and gamma herpesviruses induces a cell cycle arrest at G2/M transition through inactivation of the host cyclinB/cdc2 complex. Iltoviruses encode an UL24 homolog that should fullfill this role.

Host splicing inhibition

PsHV-1 UL54 is an alternative splicing regulator of host mRNA.

Matching UniProtKB/Swiss-Prot entries

78 entries grouped by strain (browse by keywords)

All proteins are shown (view only 71 complete proteome entries)

71 entries

Psittacid herpesvirus 1 (isolate Amazon parrot/-/97-0001/1997) (PsHV-1) (Pacheco's disease virus) reference strain

PAP_PSHV1 DNA polymerase processivity factor (DNA-binding protein UL42) (Polymerase accessory protein) (PAP)
PORTL_PSHV1 Portal protein
NP04_PSHV1 Nuclear protein UL4
ORFA_PSHV1 Uncharacterized protein ORFA
ORFB_PSHV1 Uncharacterized protein ORFB
PRIM_PSHV1 DNA primase (EC 2.7.7.-)
RIR2_PSHV1 Ribonucleoside-diphosphate reductase small subunit (EC (Ribonucleotide reductase small ...
ORFD_PSHV1 Uncharacterized protein ORFD
ORFE_PSHV1 Uncharacterized protein ORFE
ORFC_PSHV1 Uncharacterized protein ORFC
RIR1_PSHV1 Ribonucleoside-diphosphate reductase large subunit (R1) (EC (Ribonucleotide reductase ...
TRM2_PSHV1 Tripartite terminase subunit 2
TRM3_PSHV1 Tripartite terminase subunit 3 (EC 3.1.-.-) (Terminase large subunit)
US03_PSHV1 Protein kinase US3 homolog (EC
VP22_PSHV1 Tegument protein VP22
UNG_PSHV1 Uracil-DNA glycosylase (UDG) (EC (UNG)
US10_PSHV1 Virion protein US10 homolog
UL24_PSHV1 Protein UL24
US02_PSHV1 Uncharacterized protein US2
SHUT_PSHV1 Virion host shutoff protein (Vhs) (EC 3.1.27.-)
UL32_PSHV1 Packaging protein UL32
TRM1_PSHV1 Tripartite terminase subunit 1
UL15B_PSHV1 Large terminase protein homolog UL15b
DNBI_PSHV1 Major DNA-binding protein
DUT_PSHV1 Deoxyuridine 5'-triphosphate nucleotidohydrolase (dUTPase) (EC (dUTP pyrophosphatase)
CVC1_PSHV1 Capsid vertex component 1
CVC2_PSHV1 Capsid vertex component 2
CEP1_PSHV1 Cytoplasmic envelopment protein 1
CEP2_PSHV1 Cytoplasmic envelopment protein 2
ICP27_PSHV1 mRNA export factor (Immediate-early protein IE63) (Infected cell protein 27) (ICP27)
ICP4_PSHV1 Major viral transcription factor ICP4 homolog
HEPA_PSHV1 DNA helicase/primase complex-associated protein (HEPA) (Primase-associated factor)
HELI_PSHV1 DNA replication helicase (EC 3.6.4.-)
SCAF_PSHV1 Capsid scaffolding protein (Capsid protein P40) (Protease precursor) (pPR) [Cleaved into: Assemblin ...
SCP_PSHV1 Small capsomere-interacting protein
TEG7_PSHV1 Tegument protein UL51
TEG3_PSHV1 Tegument protein UL14
UL01_PSHV1 Uncharacterized protein UL-1
UL13_PSHV1 Serine/threonine-protein kinase UL13 (EC
TG21_PSHV1 Tegument protein UL21
UL03_PSHV1 Uncharacterized protein UL3
TEG5_PSHV1 Tegument protein UL47 homolog
TEG2_PSHV1 Tegument protein UL11
AN_PSHV1 Alkaline nuclease (EC 3.1.-.-)
ITP_PSHV1 Inner tegument protein
GM_PSHV1 Envelope glycoprotein M (gM)
GB_PSHV1 Envelope glycoprotein B (gB)
GL_PSHV1 Envelope glycoprotein L (gL)
GN_PSHV1 Envelope glycoprotein N
KITH_PSHV1 Thymidine kinase (EC
DPOL_PSHV1 DNA polymerase catalytic subunit (EC (EC
GI_PSHV1 Envelope glycoprotein I
GH_PSHV1 Envelope glycoprotein H (gH)
GK_PSHV1 Envelope glycoprotein K (Syncytial protein)
EV45_PSHV1 Envelope protein UL45
ATI2_PSHV1 Alpha trans-inducing factor (Tegument protein UL46) (Tegument protein VP11/12)
MCP_PSHV1 Major capsid protein (MCP)
LTP_PSHV1 Large tegument protein deneddylase (EC (EC 3.4.22.-)
GC_PSHV1 Envelope glycoprotein C
GE_PSHV1 Envelope glycoprotein E (gE)
GG_PSHV1 Glycoprotein G
GD_PSHV1 Envelope glycoprotein D (gD)
ORF2_PSHV1 Uncharacterized protein sORF2
ORF3_PSHV1 Uncharacterized protein sORF3/4
NEC1_PSHV1 Nuclear egress protein 1
NEC2_PSHV1 Nuclear egress protein 2
OBP_PSHV1 Replication origin-binding protein (OBP) (OriBP)
TRX1_PSHV1 Triplex capsid protein 1
TRX2_PSHV1 Triplex capsid protein 2
UL20_PSHV1 Protein UL20
UL43_PSHV1 Membrane protein UL43

5 entries

Infectious laryngotracheitis virus (strain Thorne V882) (ILTV) (Gallid herpesvirus 1)

UL24_ILTVT Protein UL24 homolog (ORF 3)
CVC2_ILTVT Capsid vertex component 2
SCAF_ILTVT Capsid scaffolding protein (Capsid protein P40) (Protease precursor) (pPR) [Cleaved into: Assemblin ...
GB_ILTVT Envelope glycoprotein B (gB)
KITH_ILTVT Thymidine kinase (EC

1 entry

Infectious laryngotracheitis virus (strain 632) (ILTV) (Gallid herpesvirus 1)

GB_ILTV6 Envelope glycoprotein B (gB)

1 entry

Infectious laryngotracheitis virus (strain SA-2) (ILTV) (Gallid herpesvirus 1)

GB_ILTVS Envelope glycoprotein B (gB)