1aab
From Proteopedia
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NMR STRUCTURE OF RAT HMG1 HMGA FRAGMENT
Overview
HMG1 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].
About this Structure
1AAB is a Single protein structure of sequence from Rattus norvegicus. Full crystallographic information is available from OCA.
Reference
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
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