title: Recombinant human MDM2 oncoprotein shows sequence composition selectivity             for binding to both RNA and DNA.
abstract: MDM2 is a 90 kDa nucleo-phosphoprotein that binds p53 and other proteins             contributing to its oncogenic properties. Its structure includes an amino proximal             p53 binding site, a central acidic domain and a carboxy region which incorporates             Zinc and Ring Finger domains suggestive of nucleic acid binding or transcription             factor function. It has previously been reported that a bacculovirus expressed             MDM2 protein binds RNA in a sequence-specific manner through the Ring Finger domain,             however, its ability to bind DNA has yet to be examined. We report here that a             bacterially expressed human MDM2 protein binds both DNA as well as the previously             defined RNA consensus sequence. DNA binding appears selective and involves the             carboxy-terminal domain of the molecule. RNA binding is inhibited by an MDM2 specific             antibody, which recognises an epitope within the carboxy region of the protein.             Selection cloning and sequence analysis of MDM2 DNA binding sequences, unlike             RNA binding sequences, revealed no obvious DNA binding consensus sequence, but             preferential binding to oligopurine:pyrimidine-rich stretches. Our results suggest             that the observed preferential DNA binding may occur through the Zinc Finger or             in a charge-charge interaction through the Ring Finger, thereby implying potentially             different mechanisms for DNA and RNA MDM2 binding.
authors: Northern Institute for Cancer Research, Newcastle University Medical School, Newcastle-upon-Tyne, UK.
authors: Christine
authors: C
authors: Challen
authors: John J
authors: JJ
authors: Anderson
authors: Zofia M A
authors: ZM
authors: Chrzanowska-Lightowlers
authors: Robert N
authors: RN
authors: Lightowlers
authors: John
authors: J
authors: Lunec
mesh_terms: D001665:Binding Sites; D016384:Consensus Sequence; D004247:DNA / Q000235:genetics / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D006639:Histidine / Q000378:metabolism; D006801:Humans; D058619:Maltose-Binding Proteins / Q000378:metabolism; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D015513:Oncogene Proteins / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D051736:Proto-Oncogene Proteins c-mdm2 / Q000235:genetics / Q000378:metabolism*; D012313:RNA / Q000235:genetics / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D017421:Sequence Analysis / Q000379:methods; D017422:Sequence Analysis, DNA / Q000379:methods; D016335:Zinc Fingers / Q000235:genetics
chemical_list: D004268:DNA-Binding Proteins; D058619:Maltose-Binding Proteins; D009687:Nuclear Proteins; D015513:Oncogene Proteins; D016601:RNA-Binding Proteins; D011994:Recombinant Proteins; C033223:polyhistidine; D006639:Histidine; D012313:RNA; D004247:DNA; C497206:MDM2 protein, human; D051736:Proto-Oncogene Proteins c-mdm2