2geq
From Proteopedia
Crystal Structure of a p53 Core Dimer Bound to DNA
Structural highlights
Disease[P53_MOUSE] Note=p53 is found in increased amounts in a wide variety of transformed cells. p53 is frequently mutated or inactivated in many types of cancer. Function[P53_MOUSE] Acts as a tumor suppressor in many tumor types; induces growth arrest or apoptosis depending on the physiological circumstances and cell type. Involved in cell cycle regulation as a trans-activator that acts to negatively regulate cell division by controlling a set of genes required for this process. One of the activated genes is an inhibitor of cyclin-dependent kinases. Apoptosis induction seems to be mediated either by stimulation of BAX and FAS antigen expression, or by repression of Bcl-2 expression. In cooperation with mitochondrial PPIF is involved in activating oxidative stress-induced necrosis; te function is largely independent of transcription. Prevents CDK7 kinase activity when associated to CAK complex in response to DNA damage, thus stopping cell cycle progression (By similarity). Induces the transcription of long intergenic non-coding RNA p21 (lincRNA-p21) and lincRNA-Mkln1. LincRNA-p21 participates in TP53-dependent transcriptional repression leading to apoptosis, but seems to have to effect on cell-cycle regulation.[1] [2] [3] 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 PubMedThe p53 tumor suppressor protein binds to DNA as a dimer of dimers to regulate transcription of genes that mediate responses to cellular stress. We have prepared a cross-linked trapped p53 core domain dimer bound to decamer DNA and have determined its structure by x-ray crystallography to 2.3A resolution. The p53 core domain subunits bind nearly symmetrically to opposite faces of the DNA in a head-to-head fashion with a loophelix motif making sequence-specific DNA contacts and bending the DNA by about 20 degrees at the site of protein dimerization. Protein subunit interactions occur over the central DNA minor groove and involve residues from a zinc-binding region. Analysis of tumor derived p53 mutations reveals that the dimerization interface represents a third hot spot for mutation that also includes residues associated with DNA contact and protein stability. Residues associated with p53 dimer formation on DNA are poorly conserved in the p63 and p73 paralogs, possibly contributing to their functional differences. We have used the dimeric protein-DNA complex to model a dimer of p53 dimers bound to icosamer DNA that is consistent with solution bending data and suggests that p53 core domain dimer-dimer contacts are less frequently mutated in human cancer than intra-dimer contacts. Structure of the p53 core domain dimer bound to DNA.,Ho WC, Fitzgerald MX, Marmorstein R J Biol Chem. 2006 Jul 21;281(29):20494-502. Epub 2006 May 22. PMID:16717092[4] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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