The crystal structure of HpαCA and comparison with other bacterial CAs.

<p>A: Stereo diagram of the structure of the HpαCA monomer. Each element of the secondary structure is labeled. The zinc ion and AAZ molecule are shown in ball and in stick representation, respectively, to indicate the location of the active site. B, C, D, E: Dimers observed in the crystal structures of HpαCA, NgCA, SspCA and TaCA, respectively.