2mgx | pdb_00002mgx
NMR structure of SRA1p C-terminal domain
Structural highlights
Function[SRA1_HUMAN] Functional RNA which acts as a transcriptional coactivator that selectively enhances steroid receptor-mediated transactivation ligand-independently through a mechanism involving the modulating N-terminal domain (AF-1) of steroid receptors. Also mediates transcriptional coactivation of steroid receptors ligand-dependently through the steroid-binding domain (AF-2). Enhances cellular proliferation and differentiation and promotes apoptosis in vivo. May play a role in tumorigenesis.[1] [2] [3] [4] [5] Publication Abstract from PubMedSteroid receptor activator RNA protein (SRA1p) is the translation product of the bi-functional long non-coding RNA steroid receptor activator RNA 1 (SRA1) that is part of the steroid receptor coactivator-1 acetyltransferase complex and is indicated to be an epigenetic regulatory component. Previously, the SRA1p protein was suggested to contain an RNA recognition motif (RRM) domain. We have determined the solution structure of the C-terminal domain of human SRA1p by NMR spectroscopy. Our structure along with sequence comparisons among SRA1p orthologs and against authentic RRM proteins indicates that it is not an RRM domain but rather an all-helical protein with a fold more similar to the PRP18 splicing factor. NMR spectroscopy on the full SRA1p protein suggests that this structure is relevant to the native full-length context. Furthermore, molecular modeling indicates that this fold is well conserved among vertebrates. Amino acid variations in this protein seen across sequenced human genomes, including those in tumor cells, indicate that mutations that disrupt the fold occur vary rarely and highlight that its function is well conserved. SRA1p had previously been suggested to bind to the SRA1 RNA, but NMR spectra of SRA1p in the presence of its 80-nt RNA target suggest otherwise and indicate that this protein must be part of a multi-protein complex in order to recognize its proposed RNA recognition element. The C-Terminal Domain of SRA1p Has a Fold More Similar to PRP18 than to an RRM and Does Not Directly Bind to the SRA1 RNA STR7 Region.,Bilinovich SM, Davis CM, Morris DL, Ray LA, Prokop JW, Buchan GJ, Leeper TC J Mol Biol. 2014 Apr 17;426(8):1753-65. doi: 10.1016/j.jmb.2014.01.007. Epub 2014, Jan 29. PMID:24486611[6] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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