<p>The forkhead-associated (FHA) domain [<cite idref="PUB00005445"/>] is a phosphopeptide recognition domain found in many regulatory proteins. It displays specificity for phosphothreonine-containing epitopes but will also recognise phosphotyrosine with relatively high affinity. It spans approximately 80-100 amino acid residues folded into an 11-stranded beta sandwich, which sometimes contain small helical insertions between the loops connecting the strands [<cite idref="PUB00007074"/>]. </p><p>To date, genes encoding FHA-containing proteins have been identified in eubacterial and eukaryotic but not archaeal genomes. The domain is present in a diverse range of proteins, such as kinases, phosphatases, kinesins, transcription factors, RNA-binding proteins and metabolic enzymes which partake in many different cellular processes - DNA repair, signal transduction, vesicular transport and protein degradation are just a few examples.</p> Forkhead-associated (FHA) domain