2ax2

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2ax2, resolution 1.50Å ()
Ligands:
Gene: CA2 (Homo sapiens)
Activity: Carbonate dehydratase, with EC number 4.2.1.1
Resources: FirstGlance, OCA, RCSB, PDBsum
Coordinates: save as pdb, mmCIF, xml


Contents

Production and X-ray crystallographic analysis of fully deuterated human carbonic anhydrase II

Publication Abstract from PubMed

Human carbonic anhydrase II (HCA II) is a zinc metalloenzyme that catalyzes the reversible hydration and dehydration of carbon dioxide and bicarbonate, respectively. The rate-limiting step in catalysis is the intramolecular transfer of a proton between the zinc-bound solvent (H2O/OH-) and the proton-shuttling residue His64. This distance (approximately 7.5 A) is spanned by a well defined active-site solvent network stabilized by amino-acid side chains (Tyr7, Asn62, Asn67, Thr199 and Thr200). Despite the availability of high-resolution (approximately 1.0 A) X-ray crystal structures of HCA II, there is currently no definitive information available on the positions and orientations of the H atoms of the solvent network or active-site amino acids and their ionization states. In preparation for neutron diffraction studies to elucidate this hydrogen-bonding network, perdeuterated HCA II has been expressed, purified, crystallized and its X-ray structure determined to 1.5 A resolution. The refined structure is highly isomorphous with hydrogenated HCA II, especially with regard to the active-site architecture and solvent network. This work demonstrates the suitability of these crystals for neutron macromolecular crystallography.

Production and X-ray crystallographic analysis of fully deuterated human carbonic anhydrase II., Budayova-Spano M, Fisher SZ, Dauvergne MT, Agbandje-McKenna M, Silverman DN, Myles DA, McKenna R, Acta Crystallogr Sect F Struct Biol Cryst Commun. 2006 Jan 1;62(Pt 1):6-9., Epub 2005 Dec 16. PMID:16511248

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

Disease

[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.[1][2][3][4][5]

Function

[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.[6][7]

About this Structure

2ax2 is a 1 chain structure with sequence from Homo sapiens. Full crystallographic information is available from OCA.

See Also

Reference

  • Budayova-Spano M, Fisher SZ, Dauvergne MT, Agbandje-McKenna M, Silverman DN, Myles DA, McKenna R. Production and X-ray crystallographic analysis of fully deuterated human carbonic anhydrase II. Acta Crystallogr Sect F Struct Biol Cryst Commun. 2006 Jan 1;62(Pt 1):6-9., Epub 2005 Dec 16. PMID:16511248 doi:10.1107/S1744309105038248
  1. Venta PJ, Welty RJ, Johnson TM, Sly WS, Tashian RE. Carbonic anhydrase II deficiency syndrome in a Belgian family is caused by a point mutation at an invariant histidine residue (107 His----Tyr): complete structure of the normal human CA II gene. Am J Hum Genet. 1991 Nov;49(5):1082-90. PMID:1928091
  2. Roth DE, Venta PJ, Tashian RE, Sly WS. Molecular basis of human carbonic anhydrase II deficiency. Proc Natl Acad Sci U S A. 1992 Mar 1;89(5):1804-8. PMID:1542674
  3. Soda H, Yukizane S, Yoshida I, Koga Y, Aramaki S, Kato H. A point mutation in exon 3 (His 107-->Tyr) in two unrelated Japanese patients with carbonic anhydrase II deficiency with central nervous system involvement. Hum Genet. 1996 Apr;97(4):435-7. PMID:8834238
  4. Hu PY, Lim EJ, Ciccolella J, Strisciuglio P, Sly WS. Seven novel mutations in carbonic anhydrase II deficiency syndrome identified by SSCP and direct sequencing analysis. Hum Mutat. 1997;9(5):383-7. PMID:9143915 doi:<383::AID-HUMU1>3.0.CO;2-5 10.1002/(SICI)1098-1004(1997)9:5<383::AID-HUMU1>3.0.CO;2-5
  5. Shah GN, Bonapace G, Hu PY, Strisciuglio P, Sly WS. Carbonic anhydrase II deficiency syndrome (osteopetrosis with renal tubular acidosis and brain calcification): novel mutations in CA2 identified by direct sequencing expand the opportunity for genotype-phenotype correlation. Hum Mutat. 2004 Sep;24(3):272. PMID:15300855 doi:10.1002/humu.9266
  6. Briganti F, Mangani S, Scozzafava A, Vernaglione G, Supuran CT. Carbonic anhydrase catalyzes cyanamide hydration to urea: is it mimicking the physiological reaction? J Biol Inorg Chem. 1999 Oct;4(5):528-36. PMID:10550681
  7. Kim CY, Whittington DA, Chang JS, Liao J, May JA, Christianson DW. Structural aspects of isozyme selectivity in the binding of inhibitors to carbonic anhydrases II and IV. J Med Chem. 2002 Feb 14;45(4):888-93. PMID:11831900

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