4tu9
STRUCTURE OF U2AF65 VARIANT WITH BRU5G6 DNA
Structural highlights
FunctionU2AF2_HUMAN Necessary for the splicing of pre-mRNA. Induces cardiac troponin-T (TNNT2) pre-mRNA exon inclusion in muscle. Regulates the TNNT2 exon 5 inclusion through competition with MBNL1. Binds preferentially to a single-stranded structure within the polypyrimidine tract of TNNT2 intron 4 during spliceosome assembly. Required for the export of mRNA out of the nucleus, even if the mRNA is encoded by an intron-less gene. Represses the splicing of MAPT/Tau exon 10.[1] [2] [3] Publication Abstract from PubMedPurine interruptions of polypyrimidine (Py) tract splice site signals contribute to human genetic diseases. The essential splicing factor U2AF65 normally recognizes a Py tract consensus sequence preceding the major class of 3' splice sites. We found that neurofibromatosis- or retinitis pigmentosa-causing mutations in the 5' regions of Py tracts severely reduce U2AF65 affinity. Conversely, we identified a preferred binding site of U2AF65 for purine substitutions in the 3' regions of Py tracts. Based on a comparison of new U2AF65 structures bound to either A- or G-containing Py tracts with previously identified pyrimidine-containing structures, we expected to find that a D231V amino acid change in U2AF65 would specify U over other nucleotides. We found that the crystal structure of the U2AF65-D231V variant confirms favorable packing between the engineered valine and a target uracil base. The D231V amino acid change restores U2AF65 affinity for two mutated splice sites that cause human genetic diseases and successfully promotes splicing of a defective retinitis pigmentosa-causing transcript. We conclude that reduced U2AF65 binding is a molecular consequence of disease-relevant mutations, and that a structure-guided U2AF65 variant is capable of manipulating gene expression in eukaryotic cells. Structure-guided U2AF65 variant improves recognition and splicing of a defective pre-mRNA.,Agrawal AA, McLaughlin KJ, Jenkins JL, Kielkopf CL Proc Natl Acad Sci U S A. 2014 Nov 24. pii: 201412743. PMID:25422459[4] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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