HMG1 and 2: architectural DNA-binding proteins.
HMG1 and 2 (high mobility group proteins 1 and 2; renamed HMGB1 and 2) contain two DNA-binding HMG-box domains (A and B) and a long acidic C-terminal domain. They bind DNA without sequence specificity, but have a high affinity for bent or distorted DNA, and bend linear DNA. The individual A and B boxes (which, although broadly similar, show both structural and functional differences) exhibit many of the structure-specific properties of the whole protein. The acidic tail modulates the affinity of the tandem HMG boxes in HMG1 and 2 for a variety of DNA targets, including four-way junctions, but not distorted DNA minicircles, to which the proteins bind with very high affinity. HMG1 and 2 appear to play important architectural roles in the assembly of nucleoprotein complexes in a variety of biological processes, for example V(D)J recombination, the initiation of transcription, and DNA repair.
Thomas
J O
JO
Cambridge Centre for Molecular Recognition and Department of Biochemistry, 80 Tennis Court Road, Cambridge CB2 1GA, UK. jot1@bioc.cam.ac.uk
D001665:Binding Sites; D004247:DNA / Q000737:chemistry / Q000378:metabolism*; D004254:DNA Nucleotidyltransferases / Q000378:metabolism; D004260:DNA Repair; D004268:DNA-Binding Proteins / Q000378:metabolism*; D024243:HMGB1 Protein / Q000378:metabolism*; D024261:HMGB2 Protein / Q000378:metabolism*; D006609:High Mobility Group Proteins / Q000378:metabolism; D009690:Nucleic Acid Conformation; D011995:Recombination, Genetic; D013379:Substrate Specificity; D014158:Transcription, Genetic; D045567:VDJ Recombinases
D004268:DNA-Binding Proteins; D024243:HMGB1 Protein; D024261:HMGB2 Protein; D006609:High Mobility Group Proteins; D004247:DNA; D004254:DNA Nucleotidyltransferases; D045567:VDJ Recombinases