2ax2: Difference between revisions

[[Image:2ax2.gif|left|200px]]<br /><applet load="2ax2" size="350" color="white" frame="true" align="right" spinBox="true"  

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.

2AX2 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] with <scene name='pdbligand=ZN:'>ZN</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Carbonate_dehydratase Carbonate dehydratase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=4.2.1.1 4.2.1.1] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2AX2 OCA].  

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:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=16511248 16511248]

[[Category: Dauvergne, M T.]]

[[Category: Fisher, S Z.]]

[[Category: McKenna, R M.]]

[[Category: Myles, D A.A.]]

[[Category: Silverman, D N.]]

''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 16:31:54 2008''