?
 
C-terminal catalytic domain of the atypical protein serine kinase, RIO2 kinase RIO2 is present in archaea and eukaryotes. It contains an N-terminal winged helix (wHTH) domain and a C-terminal RIO kinase catalytic domain. The wHTH domain is primarily seen in DNA-binding proteins, although some wHTH domains may be involved in RNA recognition. RIO2 is essential for survival and is necessary for rRNA cleavage during 40S ribosomal subunit maturation. RIO kinases are atypical protein serine kinases containing a kinase catalytic signature, but otherwise show very little sequence similarity to typical PKs. Serine kinases catalyze the transfer of the gamma-phosphoryl group from ATP to serine residues in protein substrates. The RIO catalytic domain is truncated compared to the catalytic domains of typical PKs, with deletions of the loops responsible for substrate binding. The RIO2 kinase catalytic domain family is part of a larger superfamily, that includes the catalytic domains of other kinases such as the typical serine/threonine/tyrosine protein kinases (PKs), aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase (PI3K). |
Jiyao W et al.(2023). "The conserved domain database in 2023.",