Alignment of muscle-type PK from felis domesticus (1PKM) and oryctolagus cuniculus (1PKN) with R-type PK from human (HRPK). The alignment was generated with AMPS, as described in the Materials and Methods and drawn with the program ALSCRIPT.35 Amino acids that are completely conserved among the three PKs are shown with yellow letters in boxes shaded with magenta. Only residues of human R-type PK (56-574) corresponding to 1PKM (12-530) are shown. The secondary structure elements, α-helixes and β-strands, assigned to 1PKM are shown above the sequences as cylinders and filled arrow, respectively. The domain organization of PK is represented by filled arrows right under the secondary structure elements. Color code: the N-terminal domain N is yellow, the catalytic domain A is blue, domain B is orange, and the C-terminal twisted αβ-type domain C is pink. The numbers above the sequences are in accordance with the numbering in 1PKM, whereas the numbers beneath the sequences refer to the codon numbering of HRPK. The red-filled triangle indicates the position of residue 364 (glycine to aspartic acid mutation), and the green filled triangle indicates the position of residue 510 (arginine to glutamine mutation).