1xdc: Difference between revisions
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'''Hydrogen Bonding in Human Manganese Superoxide Dismutase containing 3-Fluorotyrosine'''<br /> | '''Hydrogen Bonding in Human Manganese Superoxide Dismutase containing 3-Fluorotyrosine'''<br /> | ||
==Overview== | ==Overview== | ||
Incorporation of 3-fluorotyrosine and site-specific mutagenesis has been | Incorporation of 3-fluorotyrosine and site-specific mutagenesis has been utilized with Fourier transform infrared (FTIR) spectroscopy and x-ray crystallography to elucidate active-site structure and the role of an active-site residue Tyr34 in human manganese superoxide dismutase (MnSOD). Calculated harmonic frequencies at the B3LYP/6-31G** level of theory for L-tyrosine and its 3-fluorine substituted analog are compared to experimental frequencies for vibrational mode assignments. Each of the nine tyrosine residues in each of the four subunits of the homotetramer of human MnSOD was replaced with 3-fluorotyrosine. The crystal structures of the unfluorinated and fluorinated wild-type MnSOD are nearly superimposable with the root mean-square deviation for 198 alpha-carbon atoms at 0.3 A. The FTIR data show distinct vibrational modes arising from 3-fluorotyrosine in MnSOD. Comparison of spectra for wild-type and Y34F MnSOD showed that the phenolic hydroxyl of Tyr34 is hydrogen bonded, acting as a proton donor in the active site. Comparison with crystal structures demonstrates that the hydroxyl of Tyr34 is a hydrogen bond donor to an adjacent water molecule; this confirms the participation of Tyr34 in a network of residues and water molecules that extends from the active site to the adjacent subunit. | ||
==About this Structure== | ==About this Structure== | ||
1XDC 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 MN as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Superoxide_dismutase Superoxide dismutase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.15.1.1 1.15.1.1] Full crystallographic information is available from [http:// | 1XDC 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=MN:'>MN</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Superoxide_dismutase Superoxide dismutase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.15.1.1 1.15.1.1] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1XDC OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: Superoxide dismutase]] | [[Category: Superoxide dismutase]] | ||
[[Category: Ayala, I.]] | [[Category: Ayala, I.]] | ||
[[Category: Cabelli, D | [[Category: Cabelli, D E.]] | ||
[[Category: Nick, H | [[Category: Nick, H S.]] | ||
[[Category: Perry, J | [[Category: Perry, J J.]] | ||
[[Category: Silverman, D | [[Category: Silverman, D N.]] | ||
[[Category: Szczepanski, J.]] | [[Category: Szczepanski, J.]] | ||
[[Category: Tainer, J | [[Category: Tainer, J A.]] | ||
[[Category: Vala, M | [[Category: Vala, M T.]] | ||
[[Category: MN]] | [[Category: MN]] | ||
[[Category: 3-fluorotyrosine]] | [[Category: 3-fluorotyrosine]] | ||
| Line 28: | Line 27: | ||
[[Category: mnsod]] | [[Category: mnsod]] | ||
''Page seeded by [http:// | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:53:34 2008'' | ||
Revision as of 16:53, 21 February 2008
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Hydrogen Bonding in Human Manganese Superoxide Dismutase containing 3-Fluorotyrosine
OverviewOverview
Incorporation of 3-fluorotyrosine and site-specific mutagenesis has been utilized with Fourier transform infrared (FTIR) spectroscopy and x-ray crystallography to elucidate active-site structure and the role of an active-site residue Tyr34 in human manganese superoxide dismutase (MnSOD). Calculated harmonic frequencies at the B3LYP/6-31G** level of theory for L-tyrosine and its 3-fluorine substituted analog are compared to experimental frequencies for vibrational mode assignments. Each of the nine tyrosine residues in each of the four subunits of the homotetramer of human MnSOD was replaced with 3-fluorotyrosine. The crystal structures of the unfluorinated and fluorinated wild-type MnSOD are nearly superimposable with the root mean-square deviation for 198 alpha-carbon atoms at 0.3 A. The FTIR data show distinct vibrational modes arising from 3-fluorotyrosine in MnSOD. Comparison of spectra for wild-type and Y34F MnSOD showed that the phenolic hydroxyl of Tyr34 is hydrogen bonded, acting as a proton donor in the active site. Comparison with crystal structures demonstrates that the hydroxyl of Tyr34 is a hydrogen bond donor to an adjacent water molecule; this confirms the participation of Tyr34 in a network of residues and water molecules that extends from the active site to the adjacent subunit.
About this StructureAbout this Structure
1XDC is a Single protein structure of sequence from Homo sapiens with as ligand. Active as Superoxide dismutase, with EC number 1.15.1.1 Full crystallographic information is available from OCA.
ReferenceReference
Hydrogen bonding in human manganese superoxide dismutase containing 3-fluorotyrosine., Ayala I, Perry JJ, Szczepanski J, Tainer JA, Vala MT, Nick HS, Silverman DN, Biophys J. 2005 Dec;89(6):4171-9. Epub 2005 Sep 8. PMID:16150974
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