forkhead associated (FHA) domain found in forkhead box protein K2 (FOXK2) and similar proteins
FOXK2, also called cellular transcription factor ILF-1, or interleukin enhancer-binding factor 1, is a transcriptional regulator that recognizes the core sequence 5'-TAAACA-3'. It binds to NFAT-like motifs (purine-rich) in the IL2 promoter. It also binds to HIV-1 long terminal repeat. FOXK2 may be involved in both positive and negative regulation of important viral and cellular promoter elements. In addition, FOXK2 plays a critical role in suppressing tumorigenesis. The FHA domain is a small phosphopeptide recognition module.
Feature 1:putative phosphopeptide binding site [polypeptide binding site]
Evidence:
Comment: based on structures of other FHA domains with bound phosphopeptide
Comment:GR at the C terminus of strand beta3, SRxH just preceding beta5, and motif SxNG in the beta6-beta7 turn indicate a canonical mode of pThr recognition.
Comment:Conserved residues are involved in binding directly to the ligand backbone and phosphate group. Non-conserved residues may determine binding specificity.
Jiyao W et al.(2023). "The conserved domain database in 2023.",