|
|
(One intermediate revision by the same user not shown) |
Line 1: |
Line 1: |
|
| |
|
| ==X-ray crystal structure of mutant N62T of human Carbonic Anhydrase II== | | ==X-ray crystal structure of mutant N62T of human Carbonic Anhydrase II== |
| <StructureSection load='3dvc' size='340' side='right' caption='[[3dvc]], [[Resolution|resolution]] 1.60Å' scene=''> | | <StructureSection load='3dvc' size='340' side='right'caption='[[3dvc]], [[Resolution|resolution]] 1.60Å' scene=''> |
| == Structural highlights == | | == Structural highlights == |
| <table><tr><td colspan='2'>[[3dvc]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/Human Human]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3DVC OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=3DVC FirstGlance]. <br> | | <table><tr><td colspan='2'>[[3dvc]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3DVC OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3DVC FirstGlance]. <br> |
| </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=ZN:ZINC+ION'>ZN</scene></td></tr> | | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.6Å</td></tr> |
| <tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[3dvb|3dvb]], [[3dvd|3dvd]], [[3dv7|3dv7]]</td></tr>
| | <tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ZN:ZINC+ION'>ZN</scene></td></tr> |
| <tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">CA2 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=9606 HUMAN])</td></tr> | | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=3dvc FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3dvc OCA], [https://pdbe.org/3dvc PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3dvc RCSB], [https://www.ebi.ac.uk/pdbsum/3dvc PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3dvc ProSAT]</span></td></tr> |
| <tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[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] </span></td></tr>
| |
| <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=3dvc FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3dvc OCA], [http://pdbe.org/3dvc PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=3dvc RCSB], [http://www.ebi.ac.uk/pdbsum/3dvc PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=3dvc ProSAT]</span></td></tr> | |
| </table> | | </table> |
| == Disease == | | == Disease == |
| [[http://www.uniprot.org/uniprot/CAH2_HUMAN CAH2_HUMAN]] Defects in CA2 are the cause of osteopetrosis autosomal recessive type 3 (OPTB3) [MIM:[http://omim.org/entry/259730 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.<ref>PMID:1928091</ref> <ref>PMID:1542674</ref> <ref>PMID:8834238</ref> <ref>PMID:9143915</ref> <ref>PMID:15300855</ref> | | [https://www.uniprot.org/uniprot/CAH2_HUMAN CAH2_HUMAN] Defects in CA2 are the cause of osteopetrosis autosomal recessive type 3 (OPTB3) [MIM:[https://omim.org/entry/259730 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.<ref>PMID:1928091</ref> <ref>PMID:1542674</ref> <ref>PMID:8834238</ref> <ref>PMID:9143915</ref> <ref>PMID:15300855</ref> |
| == Function == | | == Function == |
| [[http://www.uniprot.org/uniprot/CAH2_HUMAN 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.<ref>PMID:10550681</ref> <ref>PMID:11831900</ref> | | [https://www.uniprot.org/uniprot/CAH2_HUMAN 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.<ref>PMID:10550681</ref> <ref>PMID:11831900</ref> |
| == Evolutionary Conservation == | | == Evolutionary Conservation == |
| [[Image:Consurf_key_small.gif|200px|right]] | | [[Image:Consurf_key_small.gif|200px|right]] |
Line 24: |
Line 22: |
| </jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=3dvc ConSurf]. | | </jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=3dvc ConSurf]. |
| <div style="clear:both"></div> | | <div style="clear:both"></div> |
| <div style="background-color:#fffaf0;">
| |
| == Publication Abstract from PubMed ==
| |
| Catalysis by the zinc metalloenzyme human carbonic anhydrase II (HCA II) is limited in maximal velocity by proton transfer between His64 and the zinc-bound solvent molecule. Asn62 extends into the active site cavity of HCA II adjacent to His64 and has been shown to be one of several hydrophilic residues participating in a hydrogen-bonded solvent network within the active site. We compared several site-specific mutants of HCA II with replacements at position 62 (Ala, Val, Leu, Thr, and Asp). The efficiency of catalysis in the hydration of CO 2 for the resulting mutants has been characterized by (18)O exchange, and the structures of the mutants have been determined by X-ray crystallography to 1.5-1.7 A resolution. Each of these mutants maintained the ordered water structure observed by X-ray crystallography in the active site cavity of wild-type HCA II; hence, this water structure was not a variable in comparing with wild type the activities of mutants at residue 62. Crystal structures of wild-type and N62T HCA II showed both an inward and outward orientation of the side chain of His64; however, other mutants in this study showed predominantly inward (N62A, N62V, N62L) or predominantly outward (N62D) orientations of His64. A significant role of Asn62 in HCA II is to permit two conformations of the side chain of His64, the inward and outward, that contributes to maximal efficiency of proton transfer between the active site and solution. The site-specific mutant N62D had a mainly outward orientation of His64, yet the difference in p K a between the proton donor His64 and zinc-bound hydroxide was near zero, as in wild-type HCA II. The rate of proton transfer in catalysis by N62D HCA II was 5% that of wild type, showing that His64 mainly in the outward orientation is associated with inefficient proton transfer compared with His64 in wild type which shows both inward and outward orientations. These results emphasize the roles of the residues of the hydrophilic side of the active site cavity in maintaining efficient catalysis by carbonic anhydrase.
| |
|
| |
| Role of Hydrophilic Residues in Proton Transfer during Catalysis by Human Carbonic Anhydrase II.,Zheng J, Avvaru BS, Tu C, McKenna R, Silverman DN Biochemistry. 2008 Oct 23. PMID:18942852<ref>PMID:18942852</ref>
| |
|
| |
| From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br>
| |
| </div>
| |
| <div class="pdbe-citations 3dvc" style="background-color:#fffaf0;"></div>
| |
|
| |
|
| ==See Also== | | ==See Also== |
| *[[Carbonic anhydrase|Carbonic anhydrase]] | | *[[Carbonic anhydrase 3D structures|Carbonic anhydrase 3D structures]] |
| == References == | | == References == |
| <references/> | | <references/> |
| __TOC__ | | __TOC__ |
| </StructureSection> | | </StructureSection> |
| [[Category: Carbonate dehydratase]] | | [[Category: Homo sapiens]] |
| [[Category: Human]] | | [[Category: Large Structures]] |
| [[Category: Avvaru, B S]] | | [[Category: Avvaru BS]] |
| [[Category: Acetylation]]
| |
| [[Category: Cytoplasm]]
| |
| [[Category: Disease mutation]]
| |
| [[Category: Human carbonic anhydrase]]
| |
| [[Category: Lyase]]
| |
| [[Category: Metal-binding]]
| |
| [[Category: Polymorphism]]
| |
| [[Category: Zinc]]
| |