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| - | [[Image:12ca.gif|left|200px]]<br /> | |
| - | <applet load="12ca" size="450" color="white" frame="true" align="right" spinBox="true" | |
| - | caption="12ca, resolution 2.4Å" /> | |
| - | '''ALTERING THE MOUTH OF A HYDROPHOBIC POCKET. STRUCTURE AND KINETICS OF HUMAN CARBONIC ANHYDRASE II MUTANTS AT RESIDUE VAL-121'''<br /> | |
| | | | |
| - | ==Overview== | + | ==ALTERING THE MOUTH OF A HYDROPHOBIC POCKET. STRUCTURE AND KINETICS OF HUMAN CARBONIC ANHYDRASE II MUTANTS AT RESIDUE VAL-121== |
| - | Eleven amino acid substitutions at Val-121 of human carbonic anhydrase II, including Gly, Ala, Ser, Leu, Ile, Lys, and Arg, were constructed by, site-directed mutagenesis. This residue is at the mouth of the hydrophobic, pocket in the enzyme active site. The CO2 hydrase activity and the, p-nitrophenyl esterase activity of these CAII variants correlate with the, hydrophobicity of the residue, suggesting that the hydrophobic character, of this residue is important for catalysis. The effects of these mutations, on the steady-state kinetics for CO2 hydration occur mainly in kcat/Km and, Km, consistent with involvement of this residue in CO2 association. The, Val-121----Ala mutant, which exhibits about one-third normal CO2 hydrase, activity, has been studied by x-ray crystallographic methods. No, significant changes in the mutant enzyme conformation are evident relative, to the wild-type enzyme. Since Val-121 is at the mouth of the hydrophobic, pocket, its substitution by the methyl side chain of alanine makes the, pocket mouth significantly wider than that of the wild-type enzyme. Hence, although a moderately wide (and deep) pocket is important for substrate, association, a wider mouth to this pocket does not seriously compromise, the catalytic approach of CO2 toward nucleophilic zinc-bound hydroxide.
| + | <StructureSection load='12ca' size='340' side='right'caption='[[12ca]], [[Resolution|resolution]] 2.40Å' scene=''> |
| | + | == Structural highlights == |
| | + | <table><tr><td colspan='2'>[[12ca]] 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=12CA OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=12CA FirstGlance]. <br> |
| | + | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.4Å</td></tr> |
| | + | <tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=HG:MERCURY+(II)+ION'>HG</scene>, <scene name='pdbligand=ZN:ZINC+ION'>ZN</scene></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=12ca FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=12ca OCA], [https://pdbe.org/12ca PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=12ca RCSB], [https://www.ebi.ac.uk/pdbsum/12ca PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=12ca ProSAT]</span></td></tr> |
| | + | </table> |
| | + | == Disease == |
| | + | [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 == |
| | + | [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 == |
| | + | [[Image:Consurf_key_small.gif|200px|right]] |
| | + | Check<jmol> |
| | + | <jmolCheckbox> |
| | + | <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/2c/12ca_consurf.spt"</scriptWhenChecked> |
| | + | <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked> |
| | + | <text>to colour the structure by Evolutionary Conservation</text> |
| | + | </jmolCheckbox> |
| | + | </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=12ca ConSurf]. |
| | + | <div style="clear:both"></div> |
| | | | |
| - | ==Disease== | + | ==See Also== |
| - | Known disease associated with this structure: Osteopetrosis, autosomal recessive 3, with renal tubular acidosis OMIM:[[http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=611492 611492]]
| + | *[[Carbonic anhydrase 3D structures|Carbonic anhydrase 3D structures]] |
| - | | + | == References == |
| - | ==About this Structure== | + | <references/> |
| - | 12CA 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 ZN and HG as [http://en.wikipedia.org/wiki/ligands ligands]. 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://ispc.weizmann.ac.il/oca-bin/ocashort?id=12CA OCA].
| + | __TOC__ |
| - | | + | </StructureSection> |
| - | ==Reference==
| + | |
| - | Altering the mouth of a hydrophobic pocket. Structure and kinetics of human carbonic anhydrase II mutants at residue Val-121., Nair SK, Calderone TL, Christianson DW, Fierke CA, J Biol Chem. 1991 Sep 15;266(26):17320-5. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=1910042 1910042]
| + | |
| - | [[Category: Carbonate dehydratase]]
| + | |
| | [[Category: Homo sapiens]] | | [[Category: Homo sapiens]] |
| - | [[Category: Single protein]] | + | [[Category: Large Structures]] |
| - | [[Category: Christianson, D.W.]] | + | [[Category: Christianson DW]] |
| - | [[Category: Nair, S.K.]] | + | [[Category: Nair SK]] |
| - | [[Category: HG]]
| + | |
| - | [[Category: ZN]]
| + | |
| - | [[Category: lyase(oxo-acid)]]
| + | |
| - | | + | |
| - | ''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Mon Nov 12 15:52:51 2007''
| + | |
| Structural highlights
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]
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
See Also
References
- ↑ 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
- ↑ 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
- ↑ 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
- ↑ 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
- ↑ 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
- ↑ 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
- ↑ 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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