ID   BEL1_SFV3L              Reviewed;         298 AA.
AC   P27402;
DT   01-AUG-1992, integrated into UniProtKB/Swiss-Prot.
DT   01-AUG-1992, sequence version 1.
DT   03-AUG-2022, entry version 72.
DE   RecName: Full=Protein Bel-1;
DE   AltName: Full=Transactivator of spumavirus;
DE            Short=Tas;
DE   AltName: Full=Transcriptional transactivator;
GN   Name=bel1; Synonyms=taf, tas;
OS   Simian foamy virus type 3 (strain LK3) (SFVagm) (SFV-3).
OC   Viruses; Riboviria; Pararnavirae; Artverviricota; Revtraviricetes;
OC   Ortervirales; Retroviridae; Spumaretrovirinae; Spumavirus.
OX   NCBI_TaxID=11644;
OH   NCBI_TaxID=9534; Chlorocebus aethiops (Green monkey) (Cercopithecus aethiops).
OH   NCBI_TaxID=9606; Homo sapiens (Human).
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX   PubMed=1310187; DOI=10.1016/0042-6822(92)90026-l;
RA   Renne R., Friedl E., Schweizer M., Fleps U., Turek R., Neumann-Haefelin D.;
RT   "Genomic organization and expression of simian foamy virus type 3 (SFV-
RT   3).";
RL   Virology 186:597-608(1992).
CC   -!- FUNCTION: Transcriptional transactivator that activates the viral
CC       internal promoter (IP), thereby enhancing its own expression. This
CC       transactivation is repressed by nuclear factor I. Also transactivates
CC       the long terminal repeat (LTR) promoter, thereby inducing structural
CC       gene expression, initiating the late phase of infection. It is
CC       therefore a key regulator of viral gene expression. It directly binds
CC       to and activates DNA target sites of viral promoters and those of
CC       distinct cellular genes. Required for viral replication (By
CC       similarity). {ECO:0000250}.
CC   -!- SUBUNIT: Homodimer or homomultimer. Forms complexes with the host
CC       nuclear factors NFIA, NFIB, NFIC or NFIX (By similarity).
CC       {ECO:0000250}.
CC   -!- SUBCELLULAR LOCATION: Host nucleus {ECO:0000250}.
CC   -!- ALTERNATIVE PRODUCTS:
CC       Event=Alternative splicing; Named isoforms=2;
CC       Name=Bel-1;
CC         IsoId=P27402-1; Sequence=Displayed;
CC       Name=Bet;
CC         IsoId=P27402-2; Sequence=Not described;
CC   -!- SEQUENCE CAUTION:
CC       Sequence=AAA47799.1; Type=Erroneous initiation; Evidence={ECO:0000305};
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DR   EMBL; M74895; AAA47799.1; ALT_INIT; Genomic_DNA.
DR   RefSeq; YP_001956724.2; NC_010820.1.
DR   GeneID; 6386655; -.
DR   Proteomes; UP000007217; Genome.
DR   GO; GO:0042025; C:host cell nucleus; IEA:UniProtKB-SubCell.
DR   GO; GO:0003677; F:DNA binding; IEA:UniProtKB-KW.
PE   3: Inferred from homology;
KW   Activator; Alternative splicing; DNA-binding; Host nucleus;
KW   Reference proteome; Transcription; Transcription regulation.
FT   CHAIN           1..298
FT                   /note="Protein Bel-1"
FT                   /id="PRO_0000125511"
FT   DNA_BIND        91..200
FT                   /evidence="ECO:0000255"
FT   REGION          1..46
FT                   /note="Disordered"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
FT   REGION          225..298
FT                   /note="Transactivation domain"
FT                   /evidence="ECO:0000255"
FT   MOTIF           214..223
FT                   /note="Nuclear localization signal"
FT                   /evidence="ECO:0000250"
FT   COMPBIAS        1..19
FT                   /note="Basic and acidic residues"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
SQ   SEQUENCE   298 AA;  33724 MW;  7DEEDD137D6E8C6C CRC64;
     MASWEKEKEL AHLHQPEDDP LPDLSLLLDM DQFEPTEGPD SNPGAEKIYL QLQVAPGDPS
     EKTYKFGYED KEAQNPDLKM RNWVPDPEKM SKWACARLIL CGLYNAKKAK ELLKMDYDIH
     WEQSKEDSQY FEIEYHCKMC MTVIHEPMPV SYDKKTGLWI KMGPLRGDIG SVVHTCRRHY
     ERCMSALPSS GEPLKPRVRA NPVRRYREKS LIVADRPKRS RWGVAPREQP NTSSGDAMAL
     MPGPCGPFNM DPPGCLLERV PGSEPGTSEM ALAMSGGPFW EQVYRDSISG PPTGPSEN