ID   LAB_XENLA               Reviewed;         427 AA.
AC   P28049;
DT   01-AUG-1992, integrated into UniProtKB/Swiss-Prot.
DT   01-AUG-1992, sequence version 1.
DT   25-MAY-2022, entry version 110.
DE   RecName: Full=Lupus La protein homolog B;
DE   AltName: Full=La autoantigen homolog B;
DE   AltName: Full=La ribonucleoprotein B;
GN   Name=ssb-b; Synonyms=lab1;
OS   Xenopus laevis (African clawed frog).
OC   Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Amphibia;
OC   Batrachia; Anura; Pipoidea; Pipidae; Xenopodinae; Xenopus; Xenopus.
OX   NCBI_TaxID=8355;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA].
RC   TISSUE=Oocyte;
RX   PubMed=8510143; DOI=10.1006/jmbi.1993.1275;
RA   Scherly D., Stutz F., Lin-Marq N., Clarkson S.G.;
RT   "La proteins from Xenopus laevis. cDNA cloning and developmental
RT   expression.";
RL   J. Mol. Biol. 231:196-204(1993).
CC   -!- FUNCTION: La protein plays a role in the transcription of RNA
CC       polymerase III. It is most probably a transcription termination factor.
CC       Binds to the 3' termini of virtually all nascent polymerase III
CC       transcripts (By similarity). {ECO:0000250}.
CC   -!- SUBCELLULAR LOCATION: Nucleus {ECO:0000305}.
CC   -!- DEVELOPMENTAL STAGE: Barely detectable in stage I/II oocytes,
CC       accumulate in stage III/IV oocytes, then exhibit a roughly constant
CC       steady state level in mature oocytes, eggs, and early embryos.
CC   -!- PTM: Phosphorylated. {ECO:0000305}.
CC   -!- MISCELLANEOUS: There are two forms of La, LaA and LaB, in Xenopus.
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DR   EMBL; X68818; CAA48716.1; -; mRNA.
DR   PIR; S33817; S33817.
DR   AlphaFoldDB; P28049; -.
DR   SMR; P28049; -.
DR   Proteomes; UP000186698; Genome assembly.
DR   GO; GO:0005634; C:nucleus; IEA:UniProtKB-SubCell.
DR   GO; GO:1990904; C:ribonucleoprotein complex; IEA:InterPro.
DR   GO; GO:0003723; F:RNA binding; IEA:UniProtKB-KW.
DR   GO; GO:0006396; P:RNA processing; IEA:InterPro.
DR   Gene3D; 1.10.10.10; -; 1.
DR   Gene3D; 3.30.70.330; -; 2.
DR   InterPro; IPR045180; La_dom_prot.
DR   InterPro; IPR006630; La_HTH.
DR   InterPro; IPR014886; La_xRRM.
DR   InterPro; IPR002344; Lupus_La.
DR   InterPro; IPR012677; Nucleotide-bd_a/b_plait_sf.
DR   InterPro; IPR035979; RBD_domain_sf.
DR   InterPro; IPR000504; RRM_dom.
DR   InterPro; IPR036388; WH-like_DNA-bd_sf.
DR   InterPro; IPR036390; WH_DNA-bd_sf.
DR   PANTHER; PTHR22792; PTHR22792; 1.
DR   Pfam; PF05383; La; 1.
DR   Pfam; PF00076; RRM_1; 1.
DR   Pfam; PF08777; RRM_3; 1.
DR   PRINTS; PR00302; LUPUSLA.
DR   SMART; SM00715; LA; 1.
DR   SMART; SM00360; RRM; 2.
DR   SUPFAM; SSF46785; SSF46785; 1.
DR   SUPFAM; SSF54928; SSF54928; 2.
DR   PROSITE; PS50961; HTH_LA; 1.
DR   PROSITE; PS50102; RRM; 1.
DR   PROSITE; PS51939; XRRM; 1.
PE   2: Evidence at transcript level;
KW   Nucleus; Phosphoprotein; Reference proteome; RNA-binding.
FT   CHAIN           1..427
FT                   /note="Lupus La protein homolog B"
FT                   /id="PRO_0000207604"
FT   DOMAIN          6..98
FT                   /note="HTH La-type RNA-binding"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00332"
FT   DOMAIN          110..202
FT                   /note="RRM"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00176"
FT   DOMAIN          226..348
FT                   /note="xRRM"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01288"
FT   REGION          193..220
FT                   /note="Disordered"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
FT   REGION          319..427
FT                   /note="Disordered"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
FT   MOTIF           315..331
FT                   /note="Nuclear localization signal"
FT                   /evidence="ECO:0000255"
FT   COMPBIAS        339..366
FT                   /note="Basic and acidic residues"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
FT   COMPBIAS        403..427
FT                   /note="Basic and acidic residues"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
SQ   SEQUENCE   427 AA;  48996 MW;  45F3146F8934A355 CRC64;
     MAENGDKEQL DLDTKICEQI EYYFGDHNLP RDKFLKQQVL LDNGWVPLET MIKFNRLSKL
     TTDFNIILQA LKKSKTELLE INEEKCKIRR SPAKPLPELN EDYKNSFKHR SVYIKGFPTI
     TNLDEIKEWL NDKGPIENIQ MRRTLQREFK GSVFLVFNTE DGAKKFLEDK NLKYKDNDMI
     ILSREEYFAK KNEERKLNKS EEKAKSKQEK EEAQKQAEDA ERKLMEERVG CLLKFSGDLD
     NMTSREDLHA LFQTHGEIEW IDFSRGAKEG IVLFKMNAKE ALDKAKAANN DNLKLKGKNV
     KWELIEGDAE KEALKKIMEG KQESFNKRKG RDGRKFKGKG RGGKGNDSSP RKKIQFQGKK
     KTFDSSDDED DMEESESPQK VTIKAKETAG PKNGASAAPG SPKKRALDDK AEDGPAVKQS
     KTEVGDQ