This domain is found in the Type III restriction-modification EcoP15I complex, present in E. coli. The Mod subunits function as a dimer with ModA recognizing the DNA and ModB methylating the target adenine base. This domain is found in the C-terminal of the ModB subunit [1].

1: Structural basis of asymmetric DNA methylation and ATP-triggered long-range diffusion by EcoP15I. Gupta YK, Chan SH, Xu SY, Aggarwal AK; Nat Commun. 2015;6:7363. PMID:26067164