a) Alignment of the loop 6 regions of A3G (NP_068594.1), A3A (NP_663745.1) and A3A loop6 swap mutant by ClustalW2. The loop 6 region is shaded light gray and C321 is underlined. The secondary structure is derived from the A3G catalytic domain crystal structure (PDB ID: 3IR2) (17).
b) DNA deaminase activity data of the indicated recombinant proteins. The activity in the presence of DMSO carrier was set to 100% for each protein to facilitate comparison, and the relative mean activities are presented with SD.