Structure and catalytic mechanism of β-carbonic anhydrases

The β-carbonic anhydrases (β-CAs) are a structurally distinct family of carbonic anhydrase that is widely distributed in microorganisms, algae, plants, and invertebrates. Like all carbonic anhydrases, β-CAs catalyze the reaction CO2 + H2O ⇆ HCO3 (-) + H(+), and is typically associated with other enzymes that produce or utilize CO2 or HCO3 (-). β-CA is required for normal growth for many organisms. Unique among the five different families of carbonic anhydrases, β-CA is the only family of carbonic anhydrase to exhibit allostery. This chapter summarizes the structure, catalytic mechanism, and allosteric regulation of β-CA.