|PROSITE documentation PDOC00305 [for PROSITE entry PS50118]|
High mobility group (HMG) chromosomal proteins are a family of relatively low molecular weight non-histone components that bind DNA without sequence specificity. HMG1 (also called HMG-T in fish) and HMG2 are related proteins that have two distinguishing features: two HMG boxes (A and B), homologous folded domains of around 80 amino acid residues, and a long acidic tail containing 20 to 30 aspartic or glutamic acid residues [1,2]. The HMG box A is only found in HMG 1 and 2 proteins whereas the HMG box B is also present in various transcription factors. HMG boxes have unusual DNA binding activity. They bind preferentially to distorted DNAs, such as four-way junctions, kinked cisplatin-modified DNA, DNA bulges, and have the property to bend DNA . They can bind DNA without sequence specificity like in HMG1 and 2 or recognize a specific site.
Several structures of HMG-boxes have been solved (see <PDB:1AAB>) [3,4]. They have a common fold consisting of three α helices arranged in an "L-shape". The HMG box binds DNA through its concave face to the minor groove of B-form DNA and causes bending by partial intercalation of a hydrophobic residue close to the N-terminus of helix I [4,5].
Some proteins known to contain a HMG box are listed below:
The pattern we developed covers the second helix of the HMG box A and therefore is specific for HMG1/2 proteins. We also developed a profile that covers the whole domain and recognizes both types of HMG boxes.Last update:
December 2004 / Pattern and text revised.
PROSITE methods (with tools and information) covered by this documentation:
|1||Authors||Bustin M., Lehn D.A., Landsman D.|
|Title||Structural features of the HMG chromosomal proteins and their genes.|
|Source||Biochim. Biophys. Acta 1049:231-243(1990).|
|Title||HMG1 and 2: architectural DNA-binding proteins.|
|Source||Biochem. Soc. Trans. 29:395-401(2001).|
|3||Authors||Hardman C.H., Broadhurst R.W., Raine A.R., Grasser K.D., Thomas J.O., Laue E.D.|
|Title||Structure of the A-domain of HMG1 and its interaction with DNA as studied by heteronuclear three- and four-dimensional NMR spectroscopy.|
|4||Authors||Werner M.H., Huth J.R., Gronenborn A.M., Clore G.M.|
|Title||Molecular basis of human 46X,Y sex reversal revealed from the three-dimensional solution structure of the human SRY-DNA complex.|
|5||Authors||Love J.J., Li X., Case D.A., Giese K., Grosschedl R., Wright P.E.|
|Title||Structural basis for DNA bending by the architectural transcription factor LEF-1.|