2lxt | pdb_00002lxt
Allosteric communication in the KIX domain proceeds through dynamic re-packing of the hydrophobic core
Structural highlights
Disease[CBP_HUMAN] Note=Chromosomal aberrations involving CREBBP may be a cause of acute myeloid leukemias. Translocation t(8;16)(p11;p13) with KAT6A; translocation t(11;16)(q23;p13.3) with MLL/HRX; translocation t(10;16)(q22;p13) with KAT6B. KAT6A-CREBBP may induce leukemia by inhibiting RUNX1-mediated transcription. Defects in CREBBP are a cause of Rubinstein-Taybi syndrome type 1 (RSTS1) [MIM:180849]. RSTS1 is an autosomal dominant disorder characterized by craniofacial abnormalities, broad thumbs, broad big toes, mental retardation and a propensity for development of malignancies.[1] [2] [3] [4] [CREB1_HUMAN] Melanoma of soft part. Angiomatoid fibrous histiocytoma (AFH) [MIM:612160]: A distinct variant of malignant fibrous histiocytoma that typically occurs in children and adolescents and is manifest by nodular subcutaneous growth. Characteristic microscopic features include lobulated sheets of histiocyte-like cells intimately associated with areas of hemorrhage and cystic pseudovascular spaces, as well as a striking cuffing of inflammatory cells, mimicking a lymph node metastasis. Note=The gene represented in this entry may be involved in disease pathogenesis. A chromosomal aberration involving CREB1 is found in a patient with angiomatoid fibrous histiocytoma. Translocation t(2;22)(q33;q12) with CREB1 generates a EWSR1/CREB1 fusion gene that is most common genetic abnormality in this tumor type. Note=A CREB1 mutation has been found in a patient with multiple congenital anomalies consisting of agenesis of the corpus callosum, cerebellar hypoplasia, severe neonatal respiratory distress refractory to surfactant, thymus hypoplasia, and thyroid follicular hypoplasia (PubMed:22267179). [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.[5] [6] 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.[7] Note=A chromosomal aberration involving MLL may be a cause of chronic neutrophilic leukemia. Translocation t(4;11)(q21;q23) with SEPT11.[8] Function[CBP_HUMAN] 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.[9] [10] [11] [12] [CREB1_HUMAN] Phosphorylation-dependent transcription factor that stimulates transcription upon binding to the DNA cAMP response element (CRE), a sequence present in many viral and cellular promoters. Transcription activation is enhanced by the TORC coactivators which act independently of Ser-133 phosphorylation. Involved in different cellular processes including the synchronization of circadian rhythmicity and the differentiation of adipose 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.[13] [14] [15] [16] Publication Abstract from PubMedThe KIX domain of the transcriptional coactivator CREB binding protein (CBP) co-operatively mediates interactions between transcription factors. Binding of the transcription factor mixed-lineage leukemia (MLL) induces the formation of a low-populated conformer of KIX that resembles the conformation of the KIX domain in the presence of a second transcription factor molecule. NMR spin relaxation studies have previously shown that allosteric coupling proceeds through a network of hydrophobic core residues that bridge the two binding sites. Here we describe high-resolution NMR solution structures of the binary complex of KIX with MLL and the ternary complex of KIX formed with MLL and phosphorylated kinase inducible domain of CREB (pKID) as a second ligand. We show that binding of pKID to the binary complex of KIX with MLL is accompanied by a defined repacking of the allosteric network in the hydrophobic core of the protein. Rotamer populations derived from methyl group 13C chemical shifts reveal a dynamic contribution to the repacking process that is not captured by the structural coordinates and exemplify the dynamic nature of allosteric communication in the KIX domain. Allosteric Communication in the KIX Domain Proceeds through Dynamic Repacking of the Hydrophobic Core.,Bruschweiler S, Konrat R, Tollinger M ACS Chem Biol. 2013 May 20. PMID:23651431[17] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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