P28049 (LAB_XENLA) Reviewed, UniProtKB/Swiss-Prot

Names and origin

Protein names

Recommended name:
Lupus La protein homolog B

Alternative name(s):
La autoantigen homolog B
La ribonucleoprotein B

Gene names

Name:	ssb-b
Synonyms:	lab1

Organism

Xenopus laevis (African clawed frog)

Taxonomic identifier

8355 [NCBI]

Taxonomic lineage

cellular organisms › Eukaryota › Opisthokonta › Metazoa › Eumetazoa › Bilateria › Deuterostomia › Chordata › Craniata › Vertebrata › Gnathostomata › Teleostomi › Euteleostomi › Sarcopterygii › Tetrapoda › Amphibia › Batrachia › Anura › Pipoidea › Pipidae › Xenopodinae › Xenopus › Xenopus

Protein attributes

Sequence length	427 AA.
Sequence status	Complete.
Protein existence	Evidence at transcript level

General annotation (Comments)

Function	La protein plays a role in the transcription of RNA polymerase III. It is most probably a transcription termination factor. Binds to the 3' termini of virtually all nascent polymerase III transcripts By similarity.
Subcellular location	Nucleus Probable.
Developmental stage	Barely detectable in stage I/II oocytes, accumulate in stage III/IV oocytes, then exhibit a roughly constant steady state level in mature oocytes, eggs, and early embryos.
Post-translational modification	Phosphorylated Probable.
Miscellaneous	There are two forms of La, LaA and LaB, in Xenopus.
Sequence similarities	Contains 1 HTH La-type RNA-binding domain. Contains 1 RRM (RNA recognition motif) domain.

Ontologies

Keywords
Cellular component	Nucleus
Ligand	RNA-binding
PTM	Phosphoprotein
Gene Ontology (GO)
Biological_process	RNA processing Inferred from electronic annotation. Source: InterPro
Cellular_component	nucleus Inferred from electronic annotation. Source: UniProtKB-SubCell ribonucleoprotein complex Inferred from electronic annotation. Source: InterPro
Molecular_function	RNA binding Inferred from electronic annotation. Source: UniProtKB-KW nucleotide binding Inferred from electronic annotation. Source: InterPro
Complete GO annotation...

Sequence annotation (Features)

	Feature key	Position(s)	Length	Description	Graphical view	Feature identifier
Molecule processing
	Chain	1 – 427	427	Lupus La protein homolog B		PRO_0000207604
Regions
	Domain	6 – 98	93	HTH La-type RNA-binding
	Domain	110 – 202	93	RRM
	Motif	315 – 331	17	Nuclear localization signal Potential

Sequences

	Sequence		Length	Mass (Da)
	P28049 [UniParc]. Last modified August 1, 1992. Version 1. Checksum: 45F3146F8934A355	FASTA	427	48,996
	10 20 30 40 50 60 MAENGDKEQL DLDTKICEQI EYYFGDHNLP RDKFLKQQVL LDNGWVPLET MIKFNRLSKL 70 80 90 100 110 120 TTDFNIILQA LKKSKTELLE INEEKCKIRR SPAKPLPELN EDYKNSFKHR SVYIKGFPTI 130 140 150 160 170 180 TNLDEIKEWL NDKGPIENIQ MRRTLQREFK GSVFLVFNTE DGAKKFLEDK NLKYKDNDMI 190 200 210 220 230 240 ILSREEYFAK KNEERKLNKS EEKAKSKQEK EEAQKQAEDA ERKLMEERVG CLLKFSGDLD 250 260 270 280 290 300 NMTSREDLHA LFQTHGEIEW IDFSRGAKEG IVLFKMNAKE ALDKAKAANN DNLKLKGKNV 310 320 330 340 350 360 KWELIEGDAE KEALKKIMEG KQESFNKRKG RDGRKFKGKG RGGKGNDSSP RKKIQFQGKK 370 380 390 400 410 420 KTFDSSDDED DMEESESPQK VTIKAKETAG PKNGASAAPG SPKKRALDDK AEDGPAVKQS KTEVGDQ

References

[1]	"La proteins from Xenopus laevis. cDNA cloning and developmental expression." Scherly D., Stutz F., Lin-Marq N., Clarkson S.G. J. Mol. Biol. 231:196-204(1993) [PubMed] [Europe PMC] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [MRNA]. Tissue: Oocyte.

Cross-references

Sequence databases
EMBL GenBank DDBJ	X68818 mRNA. Translation: CAA48716.1.
PIR	S33817.
UniGene	Xl.3639.
3D structure databases
ProteinModelPortal	P28049.
SMR	P28049. Positions 5-191, 225-331.
ModBase	Search...
Protocols and materials databases
StructuralBiologyKnowledgebase	Search...
Organism-specific databases
Xenbase	XB-GENE-866058. ssb.
Phylogenomic databases
HOVERGEN	HBG001407.
Family and domain databases
Gene3D	1.10.10.10. 1 hit. 3.30.70.330. 2 hits.
InterPro	IPR002344. Lupus_La. IPR006630. Lupus_La_RNA-bd. IPR012677. Nucleotide-bd_a/b_plait. IPR014886. RRM_3. IPR000504. RRM_dom. IPR011991. WHTH_DNA-bd_dom. [Graphical view]
Pfam	PF05383. La. 1 hit. PF00076. RRM_1. 1 hit. PF08777. RRM_3. 1 hit. [Graphical view]
PRINTS	PR00302. LUPUSLA.
SMART	SM00715. LA. 1 hit. SM00360. RRM. 1 hit. [Graphical view]
PROSITE	PS50961. HTH_LA. 1 hit. PS50102. RRM. 1 hit. [Graphical view]
ProtoNet	Search...

Entry information

Entry name

LAB_XENLA

Accession

Primary (citable) accession number: P28049

Entry history

Integrated into UniProtKB/Swiss-Prot:	August 1, 1992
Last sequence update:	August 1, 1992
Last modified:	May 1, 2013
This is version 80 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation program

Chordata Protein Annotation Program