InterPro domain: IPR008395

Fragile X Mental Retardation Protein (FMRP), and its autosomal paralogues,Fragile X mental Retardation syndrome-related protein 1 and 2 (FXR1 and FXR2),comprise a family of RNA-binding proteins. It is thought that the FRMP familyof proteins contributes to the regulation of protein synthesis at sites wheremRNAs are locally translated in response to stimuli. These proteins are highlysimilar to one another and also retain highly conserved domain architecture.The two ribonucleoprotein K homology (KH) domains and thecluster of arginine and glycine residues that constitute the RGG box, comprisea large region that is important for RNA binding and polyribosome association.In addition, two Agenet-like domains exist in tandem within the N-terminalregions of FMRP family proteins. The Agenet-like domain belongs to the "Royal"domain superfamilly which contains also the Tudor, chromo, MBT, PWWP and plantAgenet domains. Biochemical analysis of the tandem Agenet-like domains revealstheir ability to preferentially recognise trimethylated peptides in asequence-specific manner [ 1 , 2 , 3 , 4 ].

The Agenet-like domain folds into a bent four-stranded antiparallel beta sheetwith a fifth strand closing the cavity of the sheet, similar to a thumbacross a semiclosed hand [ 5 , 5 ].

1. The Tudor domain 'Royal Family': Tudor, plant Agenet, Chromo, PWWP and MBT domains. Trends Biochem. Sci. 28, 69-74
2. The N-terminus of the fragile X mental retardation protein contains a novel domain involved in dimerization and RNA binding. Biochemistry 42, 10437-44
3. The structure of the N-terminal domain of the fragile X mental retardation protein: a platform for protein-protein interaction. Structure 14, 21-31
4. Structural studies of the tandem Tudor domains of fragile X mental retardation related proteins FXR1 and FXR2. PLoS ONE 5, e13559