... atalyticfunction of the C-terminal domain is not apparent [12], and thus the role of the corresponding part of the gene is alsounknown. These g ene f usions togeth er with single-copygenes of APXs and CCPs ... conserved arginine (Arg622 in HalomarCPc) in t he corresponding position, indicating thatthese domains lost their ability to co-ordinate the heme.Further, a conserved tryptophan (Trp311 in HalomarCPn,Trp179 ... catalase–peroxid-ases had lost the ability to bind the prosthetic heme group, the structural elements remained conserved. In addition, in the N-domains of the catalase-peroxidases, there is a large,Fig....