DNA methylation at GANTC sites plays an essential role in the cell cycle of Caulobacter crescentus and related alpha-Proteobacteria, including several human pathogens. It is introduced by the Cell cycle regulated methyltransferase (CcrM). In this publication in Biochimie, we show that the CcrM contains a conserved C-terminal domain which is essential for activity. Mutation of residues in the CTD reduced activity and altered DNA binding. Our data suggest that the C-terminal domain is the so called “target recognition domain” of CcrM and based on this CcrM must be re-classified and it represents the first example of a delta-type DNA-(adenine N6)-methyltransferase.