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From Proteopedia
Structural basis for cooperative transcription factor binding to the CBP coactivator
Structural highlights
Disease[MLL1_HUMAN] Defects in MLL are the cause of Wiedemann-Steiner syndrome (WDSTS) [MIM:605130]. A syndrome characterized by hairy elbows (hypertrichosis cubiti), intellectual disability, a distinctive facial appearance, and short stature. Facial characteristics include long eyelashes, thick or arched eyebrows with a lateral flare, and downslanting and vertically narrow palpebral fissures.[1] [2] Note=Chromosomal aberrations involving MLL are a cause of acute leukemias. Translocation t(1;11)(q21;q23) with MLLT11/AF1Q; translocation t(3;11)(p21;q23) with NCKIPSD/AF3p21; translocation t(3,11)(q25,q23) with GMPS; translocation t(4;11)(q21;q23) with AFF1/MLLT2/AF4; insertion ins(5;11)(q31;q13q23) with AFF4/AF5Q31; translocation t(5;11)(q12;q23) with AF5-alpha/CENPK; translocation t(6;11)(q27;q23) with MLLT4/AF6; translocation t(9;11)(p22;q23) with MLLT3/AF9; translocation t(10;11)(p11.2;q23) with ABI1; translocation t(10;11)(p12;q23) with MLLT10/AF10; t(11;15)(q23;q14) with CASC5 and ZFYVE19; translocation t(11;17)(q23;q21) with MLLT6/AF17; translocation t(11;19)(q23;p13.3) with ELL; translocation t(11;19)(q23;p13.3) with MLLT1/ENL; translocation t(11;19)(q23;p23) with GAS7; translocation t(X;11)(q13;q23) with FOXO4/AFX1. Translocation t(3;11)(q28;q23) with LPP. Translocation t(10;11)(q22;q23) with TET1. Translocation t(9;11)(q34;q23) with DAB2IP. Translocation t(4;11)(p12;q23) with FRYL. Fusion proteins MLL-MLLT1, MLL-MLLT3 and MLL-ELL interact with PPP1R15A and, on the contrary to unfused MLL, inhibit PPP1R15A-induced apoptosis.[3] Note=A chromosomal aberration involving MLL may be a cause of chronic neutrophilic leukemia. Translocation t(4;11)(q21;q23) with SEPT11.[4] Function[MYB_MOUSE] Transcriptional activator; DNA-binding protein that specifically recognize the sequence 5'-YAAC[GT]G-3'. Plays an important role in the control of proliferation and differentiation of hematopoietic progenitor cells. [MLL1_HUMAN] Histone methyltransferase that plays an essential role in early development and hematopoiesis. Catalytic subunit of the MLL1/MLL complex, a multiprotein complex that mediates both methylation of 'Lys-4' of histone H3 (H3K4me) complex and acetylation of 'Lys-16' of histone H4 (H4K16ac). In the MLL1/MLL complex, it specifically mediates H3K4me, a specific tag for epigenetic transcriptional activation. Has weak methyltransferase activity by itself, and requires other component of the MLL1/MLL complex to obtain full methyltransferase activity. Has no activity toward histone H3 phosphorylated on 'Thr-3', less activity toward H3 dimethylated on 'Arg-8' or 'Lys-9', while it has higher activity toward H3 acetylated on 'Lys-9'. Required for transcriptional activation of HOXA9. Promotes PPP1R15A-induced apoptosis.[5] [6] [7] [8] [CBP_MOUSE] Acetylates histones, giving a specific tag for transcriptional activation. Also acetylates non-histone proteins, like NCOA3 and FOXO1. Binds specifically to phosphorylated CREB and enhances its transcriptional activity toward cAMP-responsive genes. Acts as a coactivator of ALX1 in the presence of EP300 (By similarity).[9] [10] [11] [12] 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 PubMedRegulation of transcription requires interactions between transcriptional activators and transcriptional co-activator CREB binding protein (CBP). The KIX domain of CBP can bind simultaneously to two different proteins, providing an additional mechanism for transcriptional regulation. Here we describe the solution structure of the ternary complex formed by cooperative binding of activation domains from the c-Myb and mixed lineage leukemia (MLL) transcription factors to the KIX domain. The MLL and c-Myb domains form helices that bind to two distinct hydrophobic grooves on opposite faces of KIX. Compared to the binary KIX:c-Myb complex, significant changes are observed in the structure of KIX at the MLL binding interface in the ternary complex. Two regions of KIX that are disordered in the binary complex become structured in the ternary complex: a flexible loop forms intimate contacts with bound MLL, and the C-terminal helix is extended and stabilized by MLL binding. This structural change results in the formation of additional electrostatic/polar interactions between KIX and the bound c-Myb, providing a structural basis for the cooperativity observed for the ternary complex. Structural basis for cooperative transcription factor binding to the CBP coactivator.,De Guzman RN, Goto NK, Dyson HJ, Wright PE J Mol Biol. 2006 Feb 3;355(5):1005-13. Epub 2005 Oct 5. PMID:16253272[13] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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