|PROSITE documentation PDOC51148 [for PROSITE entry PS51148]|
The AXH (ataxin-1 and HMG-box protein 1) domain is a module of ~130 amino acids, which has been identified in ATX1 and in the apparently unrelated transcription factor HBP1 . It is found in many vertebrate and invertebrate proteins. It has been suggested that the AXH domain is a molecular scaffold domain engaged in multiple protein-protein interactions and in RNA binding.
The AXH domain consists of a noncanonical oligonucleotide and oligosaccharide binding (OB) fold. Although sharing a similar OB fold, the structure of the AXH domains from ATX1 (see <PDB:1OA8>) and HBP1 (see <PDB:1V06>) have genuinely distinct folds. The differences are not, as in other chameleon sequences, determined by a different tendency to adopt distinct secondary structures: the two folds share the same secondary structure elements, but these are differently arranged in space. The AXH domain has a chameleon structure in which the N and C termini can adopt distinctly different conformation. Neither of the differences are induced by binding to another molecule. While clearly correlated (sharing a sequence identity of ca. 30% and a homology of ca. 50% depending on the species), AXH has slightly different domain boundaries and distinct properties in ATX1 and HBP1. There is a cluster of charged residues that could constitute a ligand-binding site [2,3].
Some proteins known to contain a AXH domain are listed below:
The profile we developed covers the entire AXH domain.Last update:
October 2005 / First entry.
PROSITE method (with tools and information) covered by this documentation:
|1||Authors||de Chiara C. Giannini C. Adinolfi S. de Boer J. Guida S. Ramos A. Jodice C. Kioussis D. Pastore A.|
|Title||The AXH module: an independently folded domain common to ataxin-1 and HBP1.|
|Source||FEBS Lett. 551:107-112(2003).|
|2||Authors||Chen Y.W. Allen M.D. Veprintsev D.B. Loewe J. Bycroft M.|
|Title||The structure of the AXH domain of spinocerebellar ataxin-1.|
|Source||J. Biol. Chem. 279:3758-3765(2004).|
|3||Authors||de Chiara C. Menon R.P. Adinolfi S. de Boer J. Ktistaki E. Kelly G. Calder L. Kioussis D. Pastore A.|
|Title||The AXH domain adopts alternative folds the solution structure of HBP1 AXH.|
|4||Authors||Mizutani A. Wang L. Rajan H. Vig P.J.S. Alaynick W.A. Thaler J.P. Tsai C.-C.|
|Title||Boat, an AXH domain protein, suppresses the cytotoxicity of mutant ataxin-1.|
|Source||EMBO J. 24:3339-3351(2005).|