C-terminal helicase domain of EcoR124I HsdR-like restriction enzyme family helicases
This family is composed of helicase restriction enzymes, including the HsdR subunit of restriction-modification enzymes such as Escherichia coli type I restriction enzyme EcoR124I R protein. EcoR124I recognizes the sequence, 5'-GAAN(6)RTCG-3', and cleaves at random sites. The HsdR or R subunit is required for both nuclease and ATPase activities, but not for modification. These proteins are DEAD-like helicases belonging to superfamily (SF)2, a diverse family of proteins involved in ATP-dependent RNA or DNA unwinding. Similar to SF1 helicases, SF2 helicases do not form toroidal structures like SF3-6 helicases. Their helicase core consists of two similar protein domains that resemble the fold of the recombination protein RecA. This model describes the C-terminal domain, also called HelicC.
Jiyao W et al.(2023). "The conserved domain database in 2023.",