ID   TAT_EIAVC               Reviewed;          75 AA.
AC   P32544;
DT   01-OCT-1993, integrated into UniProtKB/Swiss-Prot.
DT   23-JAN-2007, sequence version 2.
DT   29-SEP-2021, entry version 87.
DE   RecName: Full=Protein Tat;
DE   AltName: Full=E-Tat;
DE   AltName: Full=Transactivating regulatory protein;
DE   AltName: Full=eTat;
GN   Name=tat;
OS   Equine infectious anemia virus (isolate CL22) (EIAV).
OC   Viruses; Riboviria; Pararnavirae; Artverviricota; Revtraviricetes;
OC   Ortervirales; Retroviridae; Orthoretrovirinae; Lentivirus.
OX   NCBI_TaxID=31675;
OH   NCBI_TaxID=9793; Equus asinus (Donkey) (Equus africanus asinus).
OH   NCBI_TaxID=9796; Equus caballus (Horse).
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC RNA].
RX   PubMed=1318398; DOI=10.1128/jvi.66.7.4085-4097.1992;
RA   Perry S.T., Flaherty M.T., Kelley M.J., Clabough D.L., Tronick S.R.,
RA   Coggins L., Whetter L., Lengel C.R., Fuller F.;
RT   "The surface envelope protein gene region of equine infectious anemia virus
RT   is not an important determinant of tropism in vitro.";
RL   J. Virol. 66:4085-4097(1992).
CC   -!- FUNCTION: Nuclear transcriptional activator of viral gene expression,
CC       that is essential for viral transcription from the LTR promoter and
CC       replication. Acts as a sequence-specific molecular adapter, directing
CC       components of the cellular transcription machinery to the viral RNA to
CC       enhance transcription by the RNA polymerase II (RNA pol II) complex,
CC       thereby increasing the level of full-length transcripts. Tat associates
CC       with the CCNT1/cyclin-T1 component of the P-TEFb complex (CDK9 and
CC       CCNT1), which promotes RNA chain elongation. This binding increases
CC       Tat's affinity for a branched hairpin structure at the 5'-end of all
CC       nascent viral mRNAs referred to as the transactivation responsive RNA
CC       element (TAR RNA). The CDK9 component of P-TEFb hyperphosphorylates the
CC       C-terminus of RNA Pol II that becomes stabilized and much more
CC       processive (By similarity). {ECO:0000250}.
CC   -!- SUBUNIT: Binds to equine CCNT1. Participates in the formation of a
CC       complex composed at least of Tat, P-TEFb, TAR RNA, RNA Pol II (By
CC       similarity). {ECO:0000250}.
CC   -!- SUBCELLULAR LOCATION: Host nucleus, host nucleolus {ECO:0000250}.
CC   -!- SIMILARITY: Belongs to the lentiviruses Tat family. {ECO:0000305}.
CC   -!- SEQUENCE CAUTION:
CC       Sequence=AAA43030.1; Type=Erroneous initiation; Evidence={ECO:0000305};
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DR   EMBL; M87586; AAA43030.1; ALT_INIT; Genomic_RNA.
DR   EMBL; M87581; -; NOT_ANNOTATED_CDS; Genomic_RNA.
DR   PIR; A46357; TNLJS1.
DR   PDB; 2PK2; X-ray; 2.67 A; A/B/C/D=19-75.
DR   PDBsum; 2PK2; -.
DR   SMR; P32544; -.
DR   EvolutionaryTrace; P32544; -.
DR   GO; GO:0044196; C:host cell nucleolus; IEA:UniProtKB-SubCell.
DR   GO; GO:0003723; F:RNA binding; IEA:UniProtKB-KW.
DR   GO; GO:0001070; F:RNA-binding transcription regulator activity; IEA:InterPro.
DR   GO; GO:0050434; P:positive regulation of viral transcription; IEA:InterPro.
DR   InterPro; IPR001831; IV_Tat.
DR   Pfam; PF00539; Tat; 1.
PE   1: Evidence at protein level;
KW   3D-structure; Activator; Host nucleus; Host-virus interaction; RNA-binding;
KW   Transcription; Transcription regulation.
FT   CHAIN           1..75
FT                   /note="Protein Tat"
FT                   /id="PRO_0000085487"
FT   REGION          1..30
FT                   /note="Disordered"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
FT   REGION          35..49
FT                   /note="Core"
FT                   /evidence="ECO:0000250"
FT   REGION          55..75
FT                   /note="RNA-binding (TAR)"
FT                   /evidence="ECO:0000250"
FT   MOTIF           55..63
FT                   /note="Nuclear localization signal"
FT                   /evidence="ECO:0000250"
FT   COMPBIAS        11..30
FT                   /note="Polar residues"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
SQ   SEQUENCE   75 AA;  8414 MW;  F5AD0FCF2D23FBCE CRC64;
     MADRRIPGTA EENLQKSSGG VPGQNTGGQE ARPNYHCQLC FLRSLGIDYL DASLRKKNKQ
     RLKAIQQGRQ PQYLL