ID   SHDAG_HDVP1             Reviewed;         194 AA.
AC   Q81842; Q81843;
DT   01-MAR-2004, integrated into UniProtKB/Swiss-Prot.
DT   14-APR-2009, sequence version 2.
DT   03-AUG-2022, entry version 88.
DE   RecName: Full=Small delta antigen;
DE            Short=S-HDAg;
DE   AltName: Full=p24;
OS   Hepatitis delta virus genotype III (isolate Peru-1) (HDV).
OC   Viruses; Ribozyviria; Kolmioviridae; Deltavirus.
OX   NCBI_TaxID=261996;
OH   NCBI_TaxID=9606; Homo sapiens (Human).
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC RNA], AND RNA EDITING.
RX   PubMed=8415646; DOI=10.1073/pnas.90.19.9016;
RA   Casey J.L., Brown T.L., Colan E.J., Wignall F.S., Gerin J.L.;
RT   "A genotype of hepatitis D virus that occurs in northern South America.";
RL   Proc. Natl. Acad. Sci. U.S.A. 90:9016-9020(1993).
RN   [2]
RP   RNA EDITING.
RX   PubMed=12829818; DOI=10.1128/jvi.77.14.7786-7795.2003;
RA   Cheng Q., Jayan G.C., Casey J.L.;
RT   "Differential inhibition of RNA editing in hepatitis delta virus genotype
RT   III by the short and long forms of hepatitis delta antigen.";
RL   J. Virol. 77:7786-7795(2003).
RN   [3]
RP   REVIEW.
RX   PubMed=16402678;
RA   Husa P., Linhartova A., Nemecek V., Husova L.;
RT   "Hepatitis D.";
RL   Acta Virol. 49:219-225(2005).
RN   [4]
RP   REVIEW.
RX   PubMed=16903222; DOI=10.1007/3-540-29802-9_5;
RA   Huang W.H., Chen C.W., Wu H.L., Chen P.J.;
RT   "Post-translational modification of delta antigen of hepatitis D virus.";
RL   Curr. Top. Microbiol. Immunol. 307:91-112(2006).
CC   -!- FUNCTION: Promotes both transcription and replication of genomic RNA.
CC       Following virus entry into host cell, provides nuclear import of HDV
CC       RNPs thanks to its nuclear localization signal. May interact with host
CC       RNA polymerase II thereby changing its template requirement from DNA to
CC       RNA. RNA pol II complex would then acts as an RNA-directed RNA
CC       polymerase, and transcribe and replicate HDV genome (By similarity).
CC       {ECO:0000250}.
CC   -!- SUBUNIT: Homodimer. Homooctamer. Interacts with host RNA polymerase II
CC       complex, and with host NPM1. {ECO:0000250}.
CC   -!- SUBCELLULAR LOCATION: Virion. Host nucleus {ECO:0000250}.
CC   -!- PTM: Phosphorylated at serines and threonines by host MAPK1/3, PKR, and
CC       CK2. {ECO:0000250}.
CC   -!- PTM: Acetylation modulates nuclear localization. Neo-synthesized
CC       genomic RNA migrates from the nucleus to the cytoplasm, where they
CC       interact with S-HDAg, which once acetylated redirect both partners to
CC       the nucleus (By similarity). {ECO:0000250}.
CC   -!- PTM: Methylation plays a role in viral genome replication.
CC       {ECO:0000250}.
CC   -!- RNA EDITING: Modified_positions=196 {ECO:0000269|PubMed:12829818,
CC       ECO:0000269|PubMed:8415646}; Note=Partially edited. RNA editing at this
CC       position occurs on the antigenomic strand and consists of a conversion
CC       of A to G catalyzed by the cellular enzyme ADAR1. The unedited RNA
CC       version gives rise to the small delta antigen, which ends with a
CC       nonsense codon at position 196. In the edited version, this amber codon
CC       is modified to a tryptophan codon and gives rise to the large delta
CC       antigen protein (AC P0C6M3). S-HDAg suppresses editing of non-
CC       replicating antigenomic RNA, thereby regulating the extent of editing
CC       (By similarity). {ECO:0000250};
CC   -!- MISCELLANEOUS: This strain belongs to the genotype III found only among
CC       cases in South America and which causes a more severe form of infection
CC       than genotypes I and II.
CC   -!- SIMILARITY: Belongs to the hepatitis delta antigen family.
CC       {ECO:0000305}.
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DR   EMBL; L22063; AAB02596.1; -; Genomic_RNA.
DR   SMR; Q81842; -.
DR   Proteomes; UP000008110; Genome.
DR   GO; GO:0042025; C:host cell nucleus; IEA:UniProtKB-SubCell.
DR   GO; GO:0003723; F:RNA binding; IEA:UniProtKB-KW.
DR   GO; GO:0046718; P:viral entry into host cell; IEA:UniProtKB-KW.
DR   GO; GO:0075732; P:viral penetration into host nucleus; IEA:UniProtKB-KW.
DR   Gene3D; 4.10.220.40; -; 1.
DR   InterPro; IPR027403; Delta_antigen_N.
DR   InterPro; IPR037517; HDAG_dom.
DR   InterPro; IPR002506; HDV_ag.
DR   Pfam; PF01517; HDV_ag; 1.
DR   SUPFAM; SSF58108; SSF58108; 1.
DR   PROSITE; PS51838; HDAG; 1.
PE   3: Inferred from homology;
KW   Acetylation; Host nucleus; Host-virus interaction; Methylation;
KW   Phosphoprotein; Reference proteome; RNA editing; RNA-binding;
KW   Viral penetration into host nucleus; Virion; Virus entry into host cell.
FT   CHAIN           1..194
FT                   /note="Small delta antigen"
FT                   /id="PRO_0000038143"
FT   DOMAIN          20..194
FT                   /note="HDAg"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01183"
FT   REGION          12..59
FT                   /note="Dimerization"
FT                   /evidence="ECO:0000255"
FT   REGION          57..194
FT                   /note="Disordered"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
FT   REGION          96..106
FT                   /note="RNA-binding"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01183"
FT   REGION          129..194
FT                   /note="RNAPII-binding"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01183"
FT   REGION          135..145
FT                   /note="RNA-binding"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01183"
FT   MOTIF           65..74
FT                   /note="Nuclear localization signal"
FT                   /evidence="ECO:0000250|UniProtKB:P0C6L3"
FT   COMPBIAS        57..103
FT                   /note="Basic and acidic residues"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
FT   COMPBIAS        110..145
FT                   /note="Basic and acidic residues"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
FT   MOD_RES         2
FT                   /note="Phosphoserine; by host CK2"
FT                   /evidence="ECO:0000250|UniProtKB:P0C6L3"
FT   MOD_RES         13
FT                   /note="Omega-N-methylated arginine; by host PRMT1"
FT                   /evidence="ECO:0000250|UniProtKB:P0C6L3"
FT   MOD_RES         71
FT                   /note="N6-acetyllysine; by host"
FT                   /evidence="ECO:0000250|UniProtKB:P0C6L3"
FT   MOD_RES         122
FT                   /note="Phosphoserine; by host"
FT                   /evidence="ECO:0000250|UniProtKB:P0C6L3"
FT   MOD_RES         176
FT                   /note="Phosphoserine; by host MAPK1 and MAPK3"
FT                   /evidence="ECO:0000250|UniProtKB:P0C6L3"
FT   MOD_RES         181
FT                   /note="Phosphothreonine; by host"
FT                   /evidence="ECO:0000250|UniProtKB:P0C6L3"
SQ   SEQUENCE   194 AA;  22126 MW;  F7D990AF6DCA30D7 CRC64;
     MSQTVARLTS KEREEILEQW VEERKNRRKL EKDLRRANKK IKKLEDENPW LGNVVGLLRR
     KKDEDGAPPA KRPRQETMEV DSGPGRKPKA RGFTDQERRD HRRRKALENK KKQLAGGGKH
     LSQEEEEELR RLARDDDERE RRTAGPRPGG VNPMDGPPRG APGGGFVPSL QGVPESPFSR
     TGEGIDIRGT QQFP