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NMR STRUCTURE OF RAT HMG1 HMGA FRAGMENT
Structural highlights
FunctionHMGB1_RAT DNA binding proteins that associates with chromatin and has the ability to bend DNA. Binds preferentially single-stranded DNA. Involved in V(D)J recombination by acting as a cofactor of the RAG complex. Acts by stimulating cleavage and RAG protein binding at the 23 bp spacer of conserved recombination signal sequences (RSS). Heparin-binding protein that has a role in the extension of neurite-type cytoplasmic processes in developing cells (By similarity). 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 PubMedHMG1 has two homologous, folded DNA-binding domains ("HMG boxes"), A and B, linked by a short basic region to an acidic C-terminal domain. Like the whole protein, which may perform an architectural role in chromatin, the individual boxes bind to DNA without sequence specificity, have a preference for distorted or prebent DNA, and are able to bend DNA and constrain negative superhelical turns. They show qualitatively similar properties with quantitative differences. We have previously determined the structure of the HMG box from the central B-domain (77 residues) by two-dimensional NMR spectroscopy, which showed that it contains a novel fold [Weir et al. (1993) EMBO J. 12, 1311-1319]. We have now determined the structure of the A-domain (as a Cys-->Ser mutant at position 22 to avoid oxidation, without effect on its DNA-binding properties or structure) using heteronuclear three- and four-dimensional NMR spectroscopy. The A-domain has a very similar global fold to the B-domain and the Drosophila protein HMG-D [Jones et al. (1994) Structure 2, 609-627]. There are small differences between A and B, in particular in the orientation of helix I, where the B-domain is more similar to HMG-D than it is to the A-domain; these differences may turn out to be related to the subtle differences in functional properties between the two domains [Teo et al. (1995) Eur. J. Biochem. 230, 943-950] and will be the subject of further investigation. NMR studies of the interaction of the A-domain of HMG1 with a short double-stranded oligonucleotide support the notion that the protein binds via the concave face of the L-shaped structure; extensive contacts with the DNA are made by the N-terminal extended strand, the N-terminus of helix I, and the C-terminus of helix II. These contacts are very similar to those seen in the LEF-1 and SRY-DNA complexes [Love et al. (1995) Nature 376, 791-795; Werner et al. (1995) Cell 81, 705-714]. Structure of the A-domain of HMG1 and its interaction with DNA as studied by heteronuclear three- and four-dimensional NMR spectroscopy.,Hardman CH, Broadhurst RW, Raine AR, Grasser KD, Thomas JO, Laue ED Biochemistry. 1995 Dec 26;34(51):16596-607. PMID:8527432[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences | ||||||||||||||||||
