3dxb | pdb_00003dxb
Structure of the UHM domain of Puf60 fused to thioredoxin
Structural highlights
FunctionPUF60_HUMAN DNA- and RNA-binding protein, involved in several nuclear processes such as pre-mRNA splicing, apoptosis and transcription regulation. In association with FUBP1 regulates MYC transcription at the P2 promoter through the core-TFIIH basal transcription factor. Acts as a transcriptional repressor through the core-TFIIH basal transcription factor. Represses FUBP1-induced transcriptional activation but not basal transcription. Decreases ERCC3 helicase activity. Does not repress TFIIH-mediated transcription in xeroderma pigmentosum complementation group B (XPB) cells. Is also involved in pre-mRNA splicing. Promotes splicing of an intron with weak 3'-splice site and pyrimidine tract in a cooperative manner with U2AF2. Involved in apoptosis induction when overexpressed in HeLa cells. Isoform 6 failed to repress MYC transcription and inhibited FIR-induced apoptosis in colorectal cancer. Isoform 6 may contribute to tumor progression by enabling increased MYC expression and greater resistance to apoptosis in tumors than in normal cells. Modulates alternative splicing of several mRNAs. Binds to relaxed DNA of active promoter regions. Binds to the pyrimidine tract and 3'-splice site regions of pre-mRNA; binding is enhanced in presence of U2AF2. Binds to Y5 RNA in association with TROVE2. Binds to poly(U) RNA.[1] [2] [3] [4] [5] [6] THIO_ECO57 Participates in various redox reactions through the reversible oxidation of its active center dithiol to a disulfide and catalyzes dithiol-disulfide exchange reactions (By similarity). Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedPUF60 is an essential splicing factor functionally related and homologous to U2AF(65). Its C-terminal domain belongs to the family of U2AF (U2 auxiliary factor) homology motifs (UHM), a subgroup of RNA recognition motifs that bind to tryptophan-containing linear peptide motifs (UHM ligand motifs, ULMs) in several nuclear proteins. Here, we show that the Puf60 UHM is mainly monomeric in physiological buffer, whereas its dimerization is induced upon the addition of SDS. The crystal structure of PUF60-UHM at 2.2 angstroms resolution, NMR data, and mutational analysis reveal that the dimer interface is mediated by electrostatic interactions involving a flexible loop. Using glutathione S-transferase pulldown experiments, isothermal titration calorimetry, and NMR titrations, we find that Puf60-UHM binds to ULM sequences in the splicing factors SF1, U2AF65, and SF3b155. Compared with U2AF65-UHM, Puf60-UHM has distinct binding preferences to ULMs in the N terminus of SF3b155. Our data suggest that the functional cooperativity between U2AF65 and Puf60 may involve simultaneous interactions of the two proteins with SF3b155. Dimerization and protein binding specificity of the U2AF homology motif of the splicing factor Puf60.,Corsini L, Hothorn M, Stier G, Rybin V, Scheffzek K, Gibson TJ, Sattler M J Biol Chem. 2009 Jan 2;284(1):630-9. Epub 2008 Oct 29. PMID:18974054[7] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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