Enveloped, spherical to pleomorphic, 150-200 nm in diameter, T=16 icosahedral symmetry. Capsid consists of 162 capsomers and is surrounded by an amorphous tegument. Glycoproteins complexes are embedded in the lipid envelope.


Monopartite, linear, dsDNA genome of about 200 kb. The genome contains terminal and internal reiterated sequences.


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’ untranslated 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.



Lytic replication:

  1. Attachment of the viral glycoproteins to host receptors mediates endocytosis of the virus into the host cell.
  2. Entry into host cell is still unclear and may depend on the host cell type, i.e. endocytosis versus fusion at the plasma membrane.
  3. The capsid is transported to the nuclear pore where the viral DNA is released into the nucleus.
  4. Occasionally, the viral genome can be integrated in host chromosome thereby creating a latent virus.
  5. Transcription of immediate early genes which promote transcription of early genes and protect the virus against innate host immunity.
  6. Transcription of early viral mRNA by host polymerase II, encoding proteins involved in replication of the viral DNA.
  7. A first round of circular genome amplification occurs by bidirectional replication
  8. Synthesis of linear concatemer copies of viral DNA by rolling circle.
  9. Transcription of late mRNAs by host polymerase II, encoding structural proteins.
  10. 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

Adaptive immune response inhibition

The HHV-6 U24 protein downregulates the T-cell receptor complex and impairs T-cell activation.

Cell-cycle modulation

The UL24 protein homolog induces a cell cycle arrest at G2/M transition through inactivation of the host cyclinB/cdc2 complex .

Innate immune response inhibition

HHV-6 protein IE1 interferes with the binding of IRF3 to the IFN-beta promoter, reduces levels of dimerized IRF3 and nucleus-translocated IRF3 in response to activation by TBK1. This inhibiton of the pathway through IRF3 subsequenty prevents the expression IFN-beta.

Host splicing inhibition

HHV-6 UL42 modulates the host mRNA expression by exporting unspliced mRNA, thereby inducing alternative splicing .

Matching UniProtKB/Swiss-Prot entries

275 entries grouped by strain (browse by keywords)

All proteins are shown (view only 262 complete proteome entries)

101 entries

Human herpesvirus 6A (strain Uganda-1102) (HHV-6 variant A) (Human B lymphotropic virus) reference strain

Select_all Deselect_all  
AN_HHV6UAlkaline nuclease (EC 3.1.-.-)
CCU83_HHV6UPutative CC-type chemokine U83
CEP1_HHV6UCytoplasmic envelopment protein 1
CEP2_HHV6UCytoplasmic envelopment protein 2
CEP3_HHV6UCytoplasmic envelopment protein 3
CVC1_HHV6UCapsid vertex component 1
CVC2_HHV6UCapsid vertex component 2
DNBI_HHV6UMajor DNA-binding protein
DPOL_HHV6UDNA polymerase catalytic subunit (EC
DR1_HHV6UUncharacterized protein DR1
DR2_HHV6UUncharacterized protein DR2
DR3_HHV6UUncharacterized protein DR3
DR4_HHV6UUncharacterized protein DR4
DR5_HHV6UUncharacterized protein DR5
DR6_HHV6UUncharacterized protein DR6
DR7_HHV6UUncharacterized protein DR7
DR8_HHV6UUncharacterized protein DR8
DUT_HHV6UDeoxyuridine 5'-triphosphate nucleotidohydrolase (dUTPase) (EC (dUTP ...
GB_HHV6UEnvelope glycoprotein B (gB)
GCVK_HHV6UProbable ganciclovir kinase (EC 2.7.1.-)
GH_HHV6UEnvelope glycoprotein H (gH)
GL_HHV6UEnvelope glycoprotein L (gL)
GM_HHV6UEnvelope glycoprotein M (gM)
GN_HHV6UEnvelope glycoprotein N
GQ1_HHV6UGlycoprotein Q1 (gQ1) (Glycoprotein 105) (gp105) (Glycoprotein Q-80k) (gQ-80k) ...
GQ2_HHV6UGlycoprotein Q2 (gQ2) (Glycoprotein Q-37k) (gQ-37k)
HELI_HHV6UDNA replication helicase (EC 3.6.4.-)
HEPA_HHV6UDNA helicase/primase complex-associated protein (HEPA) (Primase-associated ...
ICP27_HHV6UmRNA export factor ICP27 homolog
IE1_HHV6UImmediate-early protein 1 (IE1) (Protein RF2/RF3/RF4) (pRF2/pRF3/pRF4)
IE2_HHV6UImmediate-early protein 2 (IE2)
ITP_HHV6UInner tegument protein
LJ1_HHV6UUncharacterized protein LJ1
LTP_HHV6ULarge tegument protein deneddylase (EC (EC 3.4.22.-)
MCP_HHV6UMajor capsid protein (MCP)
NEC1_HHV6UNuclear egress protein 1
NEC2_HHV6UNuclear egress protein 2
OBP_HHV6UReplication origin-binding protein (OBP)
OX2V_HHV6UPutative OX-2 membrane glycoprotein homolog (Protein U85)
P100_HHV6ULarge structural phosphoprotein (100 kDa phosphoprotein) (pp100) (Major ...
PORTL_HHV6UPortal protein
PP85_HHV6UPhosphoprotein 85 (pp85) (Protein U14)
PRIM_HHV6UDNA primase (EC 2.7.7.-)
RIR1_HHV6URibonucleoside-diphosphate reductase large subunit-like protein
RJ1_HHV6UProtein RJ1 (Protein LT1)
SCAF_HHV6UCapsid scaffolding protein (Capsid protein P40) (Protease precursor) (pPR)
SCP_HHV6USmall capsomere-interacting protein
TEG7_HHV6UTegument protein UL51 homolog
TRM1_HHV6UTripartite terminase subunit 1
TRM2_HHV6UTripartite terminase subunit 2
TRM3_HHV6UTripartite terminase subunit 3 (EC 3.1.-.-) (Terminase large subunit)
TRX1_HHV6UTriplex capsid protein 1
TRX2_HHV6UTriplex capsid protein 2
U13_HHV6UUncharacterized protein U13
U15_HHV6UUncharacterized protein U15
U16_HHV6UProtein U17/U16
U17_HHV6UProtein U17
U18_HHV6UPutative immediate early glycoprotein (Protein U18)
U1_HHV6UUncharacterized protein U1
U20_HHV6UGlycoprotein U20
U21_HHV6UGlycoprotein U21
U22_HHV6UGlycoprotein U22
U23_HHV6UGlycoprotein U23
U24_HHV6UGlycoprotein U24
U61_HHV6UUncharacterized protein U61
U6_HHV6UUncharacterized protein U6
U78_HHV6UUncharacterized protein U78
U79_HHV6UProtein U79/U80
U88_HHV6UUncharacterized protein U88
U91_HHV6UUncharacterized protein U91
U95_HHV6UUncharacterized protein U95
UL24_HHV6UProtein UL24 homolog
UL32_HHV6UPackaging protein UL32
UL33_HHV6UG-protein coupled receptor homolog U12
UL38_HHV6UApoptosis inhibitor U19
UL49_HHV6UProtein U33
UL79_HHV6UProtein U52
UL87_HHV6UProtein U58
UL88_HHV6UProtein U59
UL91_HHV6UProtein U62
UL92_HHV6UProtein U63
UL95_HHV6UProtein U67
UL96_HHV6UProtein U68
UNG_HHV6UUracil-DNA glycosylase (UDG) (EC (UNG)
VPAP_HHV6UDNA polymerase processivity factor (Phosphoprotein P41) (PP41) (Polymerase ...
VU10_HHV6UU10 protein
VU1_HHV6UProtein U1
VU25_HHV6UProtein U25
VU26_HHV6UProtein U26
VU3_HHV6UProtein U3
VU47_HHV6UGlycoprotein U47
VU4_HHV6UProtein U4
VU51_HHV6UG-protein coupled receptor homolog U51
VU54_HHV6UProtein U54
VU55_HHV6UUncharacterized protein U55
VU5_HHV6UProtein U5
VU7_HHV6UProtein U7
VU84_HHV6UProtein U84
VU8_HHV6UProtein U8
VU94_HHV6UProtein U94
VU9_HHV6UProtein U9

98 entries

Human herpesvirus 6B (strain Z29) (HHV-6 variant B) (Human B lymphotropic virus) reference strain

Select_all Deselect_all  
AN_HHV6ZAlkaline nuclease (EC 3.1.-.-)
B1_HHV6ZProtein B1
B2_HHV6ZProtein B2
B3_HHV6ZProtein B3
B4_HHV6ZProtein B4
B5_HHV6ZProtein B5
B6_HHV6ZProtein B6
B7_HHV6ZProtein B7
B8_HHV6ZProtein B8
B9_HHV6ZProtein B9
CCU83_HHV6ZPutative CC-type chemokine U83
CEP1_HHV6ZCytoplasmic envelopment protein 1
CEP2_HHV6ZCytoplasmic envelopment protein 2
CEP3_HHV6ZCytoplasmic envelopment protein 3
CVC1_HHV6ZCapsid vertex component 1
CVC2_HHV6ZCapsid vertex component 2
DNBI_HHV6ZMajor DNA-binding protein
DPOL_HHV6ZDNA polymerase catalytic subunit (EC
DR1_HHV6ZUncharacterized protein DR1
DR3_HHV6ZUncharacterized protein DR3
DR6_HHV6ZUncharacterized protein DR6
DUT_HHV6ZDeoxyuridine 5'-triphosphate nucleotidohydrolase (dUTPase) (EC (dUTP ...
GB_HHV6ZEnvelope glycoprotein B (gB)
GCVK_HHV6ZProbable ganciclovir kinase (EC 2.7.1.-)
GH_HHV6ZEnvelope glycoprotein H (gH)
GL_HHV6ZEnvelope glycoprotein L (gL)
GM_HHV6ZEnvelope glycoprotein M (gM)
GN_HHV6ZEnvelope glycoprotein N
GQ1_HHV6ZGlycoprotein Q1 (gQ1) (Glycoprotein 105) (gp105) (Glycoprotein Q-80k) (gQ-80k) ...
GQ2_HHV6ZGlycoprotein Q2 (gQ2)
HELI_HHV6ZDNA replication helicase (EC 3.6.4.-)
HEPA_HHV6ZDNA helicase/primase complex-associated protein (HEPA) (Primase-associated ...
ICP27_HHV6ZmRNA export factor ICP27 homolog
IE2_HHV6ZImmediate-early protein 2 (IE2)
ITP_HHV6ZInner tegument protein
LTP_HHV6ZLarge tegument protein deneddylase (EC (EC 3.4.22.-)
MCP_HHV6ZMajor capsid protein (MCP)
NEC1_HHV6ZNuclear egress protein 1
NEC2_HHV6ZNuclear egress protein 2
OBP_HHV6ZReplication origin-binding protein (OBP)
OX2V_HHV6ZPutative OX-2 membrane glycoprotein homolog (Protein U85)
P100_HHV6ZLarge structural phosphoprotein (100 kDa phosphoprotein) (pp100) (Major ...
PORTL_HHV6ZPortal protein
PP85_HHV6ZPhosphoprotein 85 (pp85) (Protein U14)
PRIM_HHV6ZDNA primase (EC 2.7.7.-)
RIR1_HHV6ZRibonucleoside-diphosphate reductase large subunit-like protein
SCAF_HHV6ZCapsid scaffolding protein (Capsid protein P40) (Protease precursor) (pPR)
SCP_HHV6ZSmall capsomere-interacting protein
TEG7_HHV6ZTegument protein UL51 homolog
TRM1_HHV6ZTripartite terminase subunit 1
TRM2_HHV6ZTripartite terminase subunit 2
TRM3_HHV6ZTripartite terminase subunit 3 (EC 3.1.-.-) (Terminase large subunit)
TRX1_HHV6ZTriplex capsid protein 1
TRX2_HHV6ZTriplex capsid protein 2
U10_HHV6ZProtein U10
U13_HHV6ZUncharacterized protein U13
U15_HHV6ZProtein U15
U17_HHV6ZProtein U17
U18_HHV6ZPutative immediate early glycoprotein (Protein U18)
U20_HHV6ZGlycoprotein U20
U21_HHV6ZU21 glycoprotein
U22_HHV6ZProtein U22
U23_HHV6ZProtein U23
U24A_HHV6ZUncharacterized protein U24A
U24_HHV6ZProtein U24
U6_HHV6ZUncharacterized protein U6
U79_HHV6ZProtein U79
U90_HHV6ZProtein U90
U91_HHV6ZProtein U91
U95_HHV6ZUncharacterized protein U95
UL24_HHV6ZProtein UL24 homolog
UL32_HHV6ZPackaging protein UL32 homolog
UL38_HHV6ZApoptosis inhibitor U19
UL49_HHV6ZProtein U33
UL79_HHV6ZProtein U52
UL87_HHV6ZProtein U58
UL88_HHV6ZProtein U59
UL91_HHV6ZProtein U62
UL92_HHV6ZProtein U63
UL95_HHV6ZProtein U67
UL96_HHV6ZProtein U68
UNG_HHV6ZUracil-DNA glycosylase (UDG) (EC (UNG)
VGCR_HHV6ZG-protein coupled receptor
VPAP_HHV6ZDNA polymerase processivity factor (Phosphoprotein P41) (PP41) (Polymerase ...
VU25_HHV6ZProtein U25
VU26_HHV6ZProtein U26
VU2_HHV6ZProtein U2
VU3_HHV6ZProtein U3
VU47_HHV6ZGlycoprotein U47
VU4_HHV6ZProtein U4
VU51_HHV6ZG-protein coupled receptor homolog U51
VU54_HHV6ZProtein U54
VU55_HHV6ZUncharacterized protein U55
VU7_HHV6ZProtein U7
VU84_HHV6ZProtein U84
VU8_HHV6ZProtein U8
VU94_HHV6ZProtein U94
VU9_HHV6ZProtein U9

62 entries

Human herpesvirus 7 (strain JI) (HHV-7) (Human T lymphotropic virus) reference strain

Select_all Deselect_all  
AN_HHV7JAlkaline nuclease (EC 3.1.-.-)
CEP1_HHV7JCytoplasmic envelopment protein 1
CEP2_HHV7JCytoplasmic envelopment protein 2
CEP3_HHV7JCytoplasmic envelopment protein 3
CVC1_HHV7JCapsid vertex component 1
CVC2_HHV7JCapsid vertex component 2
DNBI_HHV7JMajor DNA-binding protein
DPOL_HHV7JDNA polymerase catalytic subunit (EC
DUT_HHV7JDeoxyuridine 5'-triphosphate nucleotidohydrolase (dUTPase) (EC (dUTP ...
GB_HHV7JEnvelope glycoprotein B (gB)
GCVK_HHV7JProbable ganciclovir kinase (EC 2.7.1.-)
GH_HHV7JEnvelope glycoprotein H (gH)
GL_HHV7JEnvelope glycoprotein L (gL)
GM_HHV7JEnvelope glycoprotein M (gM)
GN_HHV7JEnvelope glycoprotein N
HELI_HHV7JDNA replication helicase (EC 3.6.4.-)
HEPA_HHV7JDNA helicase/primase complex-associated protein (HEPA) (Primase-associated ...
ICP27_HHV7JmRNA export factor ICP27 homolog
ITP_HHV7JInner tegument protein
LTP_HHV7JLarge tegument protein deneddylase (EC (EC 3.4.22.-)
MCP_HHV7JMajor capsid protein (MCP)
NEC1_HHV7JNuclear egress protein 1
NEC2_HHV7JNuclear egress protein 2
OBP_HHV7JReplication origin-binding protein (OBP)
P100_HHV7JLarge structural phosphoprotein (100 kDa phosphoprotein) (pp100)
PORTL_HHV7JPortal protein
PRIM_HHV7JDNA primase (EC 2.7.7.-)
RIR1_HHV7JRibonucleoside-diphosphate reductase large subunit-like protein
SCAF_HHV7JCapsid scaffolding protein (Capsid protein P40) (Protease precursor) (pPR)
TEG7_HHV7JTegument protein UL51 homolog
TRM1_HHV7JTripartite terminase subunit 1
TRM3_HHV7JTripartite terminase subunit 3 (EC 3.1.-.-) (Terminase large subunit)
TRX1_HHV7JTriplex capsid protein 1
TRX2_HHV7JTriplex capsid protein 2
U21_HHV7JU21 glycoprotein
U79_HHV7JProtein U79
UL24_HHV7JProtein UL24 homolog
UL32_HHV7JPackaging protein UL32
UL33_HHV7JG-protein coupled receptor homolog U12
UL49_HHV7JProtein U33
UL79_HHV7JProtein U52
UL87_HHV7JProtein U58
UL88_HHV7JProtein U59
UL91_HHV7JProtein U62
UL92_HHV7JProtein U63
UL95_HHV7JProtein U67
UL96_HHV7JProtein U68
UNG_HHV7JUracil-DNA glycosylase (UDG) (EC (UNG)
V55A_HHV7JUncharacterized protein U55A
V55B_HHV7JUncharacterized protein U55B
VPAP_HHV7JDNA polymerase processivity factor (Polymerase accessory protein) (PAP)
VU10_HHV7JU10 protein
VU25_HHV7JProtein U25
VU26_HHV7JProtein U26
VU3_HHV7JProtein U3
VU47_HHV7JGlycoprotein U47 homolog
VU4_HHV7JProtein U4
VU51_HHV7JG-protein coupled receptor homolog U51
VU54_HHV7JProtein U54
VU5_HHV7JProtein U5
VU84_HHV7JProtein U84
VU8_HHV7JProtein U8

11 entries

Human herpesvirus 6A (strain GS) (HHV-6 variant A) (Human B lymphotropic virus)

Select_all Deselect_all  
DUT_HHV6GDeoxyuridine 5'-triphosphate nucleotidohydrolase (dUTPase) (EC (dUTP ...
GB_HHV6GEnvelope glycoprotein B (gB)
GH_HHV6GEnvelope glycoprotein H (gH)
GP105_HHV6GGlycoprotein 105 (gp105)
IE2_HHV6GImmediate-early protein 2 (IE2)
LTP_HHV6GLarge tegument protein deneddylase (EC (EC 3.4.22.-)
U16_HHV6GProtein U17/U16
U17_HHV6GProtein U17
UL24_HHV6GProtein UL24 homolog
VU26_HHV6GProtein U26
VU47_HHV6GGlycoprotein U47

1 entry

Human herpesvirus 6B (strain HST) (HHV-6 variant B) (Human B lymphotropic virus)

U79_HHV6HProtein U79/U80

1 entry

Human herpesvirus 7 (strain MUK) (HHV-7) (Human T lymphotropic virus)

TRX2_HHV7MTriplex capsid protein 2

1 entry

Human herpesvirus 7 (strain RK) (HHV-7) (Human T lymphotropic virus)

U21_HHV7RU21 glycoprotein (gp60)