La domain

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La domain
PDB 2cqk EBI.jpg
solution structure of the la domain of c-mpl binding protein
Symbol La
Pfam PF05383
InterPro IPR006630
SCOP 2mpr
TCDB 1.B.3
CDD cd07323

In molecular biology, the La domain is a conserved protein domain.

Human 60 kDa SS-A/Ro ribonucleoproteins (RNPs) are composed of one of the four small Y RNAs and at least two proteins, Ro60 and La. The La protein is a 47 kDa polypeptide that frequently acts as an autoantigen in systemic lupus erythematosus and Sjogren's syndrome.[1] In the nucleus, La acts as a RNA polymerase III (RNAP III) transcription factor, while in the cytoplasm, La acts as a translation factor.[2] In the nucleus, La binds to the 3'UTR of nascent RNAP III transcripts to assist in folding and maturation.[3] In the cytoplasm, La recognises specific classes of mRNAs that contain a 5'-terminal oligopyrimidine (5'TOP) motif known to control protein synthesis.[4] The specific recognition is mediated by the N-terminal domain of La, which comprises a La motif and an RNA recognition motif (RRM). The La motif adopts an alpha/beta fold that comprises a winged-helix motif.[5]

Homologous La domain-containing proteins have been identified in a wide range of organisms except Archaea, bacteria and viruses.[6]


  1. ^ Izumi RE, Das S, Barat B, Raychaudhuri S, Dasgupta A (April 2004). "A peptide from autoantigen La blocks poliovirus and hepatitis C virus cap-independent translation and reveals a single tyrosine critical for La RNA binding and translation stimulation". J. Virol. 78 (7): 3763–76. doi:10.1128/jvi.78.7.3763-3776.2004. PMC 371053Freely accessible. PMID 15016896. 
  2. ^ Intine RV, Tenenbaum SA, Sakulich AL, Keene JD, Maraia RJ (November 2003). "Differential phosphorylation and subcellular localization of La RNPs associated with precursor tRNAs and translation-related mRNAs". Mol. Cell. 12 (5): 1301–7. doi:10.1016/S1097-2765(03)00429-5. PMID 14636586. 
  3. ^ Alfano C, Sanfelice D, Babon J, Kelly G, Jacks A, Curry S, Conte MR (April 2004). "Structural analysis of cooperative RNA binding by the La motif and central RRM domain of human La protein". Nat. Struct. Mol. Biol. 11 (4): 323–9. doi:10.1038/nsmb747. PMID 15004549. 
  4. ^ Keene JD (December 2003). "Posttranscriptional generation of macromolecular complexes". Mol. Cell. 12 (6): 1347–9. doi:10.1016/S1097-2765(03)00496-9. PMID 14690589. 
  5. ^ Kenan DJ, Keene JD (April 2004). "La gets its wings". Nat. Struct. Mol. Biol. 11 (4): 303–5. doi:10.1038/nsmb0404-303. PMID 15048103. 
  6. ^ Lin-Marq N, Clarkson SG (January 1995). "A yeast RNA binding protein that resembles the human autoantigen La". J. Mol. Biol. 245 (2): 81–5. doi:10.1006/jmbi.1994.0008. PMID 7799435. 

This article incorporates text from the public domain Pfam and InterPro IPR006630