6en4
SF3b core in complex with a splicing modulator
Structural highlights
Function[PHF5A_HUMAN] Acts as a transcriptional regulator by binding to the GJA1/Cx43 promoter and enhancing its up-regulation by ESR1/ER-alpha. Also involved in pre-mRNA splicing.[1] [SF3B3_HUMAN] Subunit of the splicing factor SF3B required for 'A' complex assembly formed by the stable binding of U2 snRNP to the branchpoint sequence (BPS) in pre-mRNA. Sequence independent binding of SF3A/SF3B complex upstream of the branch site is essential, it may anchor U2 snRNP to the pre-mRNA. May also be involved in the assembly of the 'E' complex. Belongs also to the minor U12-dependent spliceosome, which is involved in the splicing of rare class of nuclear pre-mRNA intron. [SF3B1_HUMAN] Subunit of the splicing factor SF3B required for 'A' complex assembly formed by the stable binding of U2 snRNP to the branchpoint sequence (BPS) in pre-mRNA. Sequence independent binding of SF3A/SF3B complex upstream of the branch site is essential, it may anchor U2 snRNP to the pre-mRNA. May also be involved in the assembly of the 'E' complex. Belongs also to the minor U12-dependent spliceosome, which is involved in the splicing of rare class of nuclear pre-mRNA intron. Publication Abstract from PubMedSF3B is a multi-protein complex essential for branch site (BS) recognition and selection during pre-mRNA splicing. Several splicing modulators with antitumor activity bind SF3B and thereby modulate splicing. Here we report the crystal structure of a human SF3B core in complex with pladienolide B (PB), a macrocyclic splicing modulator and potent inhibitor of tumor cell proliferation. PB stalls SF3B in an open conformation by acting like a wedge within a hinge, modulating SF3B's transition to the closed conformation needed to form the BS adenosine-binding pocket and stably accommodate the BS/U2 duplex. This work explains the structural basis for the splicing modulation activity of PB and related compounds, and reveals key interactions between SF3B and a common pharmacophore, providing a framework for future structure-based drug design. Structural Basis of Splicing Modulation by Antitumor Macrolide Compounds.,Cretu C, Agrawal AA, Cook A, Will CL, Fekkes P, Smith PG, Luhrmann R, Larsen N, Buonamici S, Pena V Mol Cell. 2018 Apr 19;70(2):265-273.e8. doi: 10.1016/j.molcel.2018.03.011. Epub, 2018 Apr 12. PMID:29656923[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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