ID   BEL1_FFV                Reviewed;         209 AA.
AC   O56862;
DT   11-JUL-2006, integrated into UniProtKB/Swiss-Prot.
DT   01-JUN-1998, sequence version 1.
DT   02-JUN-2021, entry version 63.
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   Feline foamy virus (FFV) (Feline syncytial virus).
OC   Viruses; Riboviria; Pararnavirae; Artverviricota; Revtraviricetes;
OC   Ortervirales; Retroviridae; Spumaretrovirinae; Felispumavirus.
OX   NCBI_TaxID=53182;
OH   NCBI_TaxID=9685; Felis catus (Cat) (Felis silvestris catus).
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX   PubMed=9261397; DOI=10.1128/jvi.71.9.6727-6741.1997;
RA   Winkler I., Bodem J., Haas L., Zemba M., Delius H., Flower R.,
RA   Fluegel R.M., Loechelt M.;
RT   "Characterization of the genome of feline foamy virus and its proteins
RT   shows distinct features different from those of primate Spumaviruses.";
RL   J. Virol. 71:6727-6741(1997).
RN   [2]
RP   NUCLEOTIDE SEQUENCE [GENOMIC RNA].
RC   STRAIN=Isolate FUV;
RX   PubMed=9601510; DOI=10.1006/viro.1998.9113;
RA   Bodem J., Loechelt M., Delius H., Fluegel R.M.;
RT   "Detection of subgenomic cDNAs and mapping of feline foamy virus mRNAs
RT   reveals complex patterns of transcription.";
RL   Virology 244:417-426(1998).
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   -!- ALTERNATIVE PRODUCTS:
CC       Event=Alternative splicing; Named isoforms=3;
CC         Comment=The first 31 residues are shared by isoforms Bet and Bel-1,
CC         the last 356 residues are shared by isoforms Bet and Bel-2.;
CC       Name=Bel-1; Synonyms=Bel1;
CC         IsoId=O56862-1; Sequence=Displayed;
CC       Name=Bet;
CC         IsoId=O93036-1; Sequence=External;
CC       Name=Bel-2; Synonyms=Bel2;
CC         IsoId=O93036-2; Sequence=External;
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DR   EMBL; Y08851; CAA70077.1; -; Genomic_DNA.
DR   EMBL; AJ223851; CAA11583.1; -; Genomic_RNA.
DR   RefSeq; NP_056917.1; NC_001871.1.
DR   Proteomes; UP000008763; Genome.
DR   Proteomes; UP000201849; Genome.
DR   GO; GO:0003677; F:DNA binding; IEA:UniProtKB-KW.
PE   3: Inferred from homology;
KW   Activator; Alternative splicing; DNA-binding; Reference proteome;
KW   Transcription; Transcription regulation.
FT   CHAIN           1..209
FT                   /note="Protein Bel-1"
FT                   /id="PRO_0000244970"
FT   REGION          1..30
FT                   /note="Disordered"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
FT   REGION          123..143
FT                   /note="Disordered"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
FT   REGION          156..185
FT                   /note="Disordered"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
FT   COMPBIAS        156..180
FT                   /note="Polar residues"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
SQ   SEQUENCE   209 AA;  23124 MW;  BCD82FABD5706B99 CRC64;
     MASKYPEEGP ITEGVEEDFN SHSTSGLDLT SGNKEEPLIS LALLSMHTSK IVVWIRDHFF
     VKILSFGGKQ KLYYICNQCH KGIPESGYIT LNTKYYLYEK GPTETGTKGL TLMRRHVQNS
     PCFLNSRKES GTPKTDPTRP ATSYSLCRSD YQEAGCSRPT PSNSESVCNG LGQPSERGHT
     SGESGGIMEE VSFISWLEGL WGEGFDYAN