From Proteopediaproteopedia link
Human carbonic anhydrase II in complex with (+)-Xylariamide A
[CAH2_HUMAN] Defects in CA2 are the cause of osteopetrosis autosomal recessive type 3 (OPTB3) [MIM:259730]; also known as osteopetrosis with renal tubular acidosis, carbonic anhydrase II deficiency syndrome, Guibaud-Vainsel syndrome or marble brain disease. Osteopetrosis is a rare genetic disease characterized by abnormally dense bone, due to defective resorption of immature bone. The disorder occurs in two forms: a severe autosomal recessive form occurring in utero, infancy, or childhood, and a benign autosomal dominant form occurring in adolescence or adulthood. Autosomal recessive osteopetrosis is usually associated with normal or elevated amount of non-functional osteoclasts. OPTB3 is associated with renal tubular acidosis, cerebral calcification (marble brain disease) and in some cases with mental retardation.    
[CAH2_HUMAN] Essential for bone resorption and osteoclast differentiation (By similarity). Reversible hydration of carbon dioxide. Can hydrate cyanamide to urea. Involved in the regulation of fluid secretion into the anterior chamber of the eye. 
Publication Abstract from PubMed
In order to discover novel probes that may help in the investigation and control of infectious diseases through a new mechanism of action, we have evaluated a library of phenol-based natural products (NPs) for enzyme inhibition against four recently characterized pathogen beta-family carbonic anhydrases (CAs). These include CAs from Mycobacterium tuberculosis, Candida albicans, and Cryptococcus neoformans as well as alpha-family human CA I and CA II for comparison. Many of the NPs selectively inhibited the mycobacterial and fungal beta-CAs, with the two best performing compounds displaying submicromolar inhibition with a preference for fungal over human CA inhibition of more than 2 orders of magnitude. These compounds provide the first example of non-sulfonamide inhibitors that display beta over alpha CA enzyme selectivity. Structural characterization of the library compounds in complex with human CA II revealed a novel binding mode whereby a methyl ester interacts via a water molecule with the active site zinc.
Natural Product-Based Phenols as Novel Probes for Mycobacterial and Fungal Carbonic Anhydrases.,Davis RA, Hofmann A, Osman A, Hall RA, Muhlschlegel FA, Vullo D, Innocenti A, Supuran CT, Poulsen SA J Med Chem. 2011 Mar 24;54(6):1682-1692. Epub 2011 Feb 18. PMID:21332115
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.