1mty: Difference between revisions
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==Overview== | ==Overview== | ||
The crystal structure of the nonheme iron-containing hydroxylase component | The crystal structure of the nonheme iron-containing hydroxylase component of methane monooxygenase hydroxylase (MMOH) from Methylococcus capsulatus (Bath) has been solved in two crystal forms, one of which was refined to 1.7 A resolution. The enzyme is composed of two copies each of three subunits (alpha 2 beta 2 gamma 2), and all three subunits are almost completely alpha-helical, with the exception of two beta hairpin structures in the alpha subunit. The active site of each alpha subunit contains one dinuclear iron center, housed in a four-helix bundle. The two iron atoms are octahedrally coordinated by 2 histidine and 4 glutamic acid residues as well as by a bridging hydroxide ion, a terminal water molecule, and at 4 degrees C, a bridging acetate ion, which is replaced at -160 degrees C with a bridging water molecule. Comparison of the results for two crystal forms demonstrates overall conservation and relative orientation of the domain structures. The most prominent structural differences identified between the two crystal forms is in an altered side chain conformation for Leu 110 at the active site cavity. We suggest that this residue serves as one component of a hydrophobic gate controlling access of substrates to and products from the active site. The leucine gate may be responsible for the effect of the B protein component on the reactivity of the reduced hydroxylase with dioxygen. A potential reductase binding site has been assigned based on an analysis of crystal packing in the two forms and corroborated by inhibition studies with a synthetic peptide corresponding to the proposed docking position. | ||
==About this Structure== | ==About this Structure== | ||
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[[Category: Methylococcus capsulatus]] | [[Category: Methylococcus capsulatus]] | ||
[[Category: Protein complex]] | [[Category: Protein complex]] | ||
[[Category: Frederick, C | [[Category: Frederick, C A.]] | ||
[[Category: Lippard, S | [[Category: Lippard, S J.]] | ||
[[Category: Nordlund, P.]] | [[Category: Nordlund, P.]] | ||
[[Category: Rosenzweig, A | [[Category: Rosenzweig, A C.]] | ||
[[Category: FE]] | [[Category: FE]] | ||
[[Category: dinuclear iron center monooxygenase]] | [[Category: dinuclear iron center monooxygenase]] | ||
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[[Category: methane monooxygenase]] | [[Category: methane monooxygenase]] | ||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:58:56 2008'' | ||
Revision as of 14:58, 21 February 2008
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METHANE MONOOXYGENASE HYDROXYLASE FROM METHYLOCOCCUS CAPSULATUS (BATH)
OverviewOverview
The crystal structure of the nonheme iron-containing hydroxylase component of methane monooxygenase hydroxylase (MMOH) from Methylococcus capsulatus (Bath) has been solved in two crystal forms, one of which was refined to 1.7 A resolution. The enzyme is composed of two copies each of three subunits (alpha 2 beta 2 gamma 2), and all three subunits are almost completely alpha-helical, with the exception of two beta hairpin structures in the alpha subunit. The active site of each alpha subunit contains one dinuclear iron center, housed in a four-helix bundle. The two iron atoms are octahedrally coordinated by 2 histidine and 4 glutamic acid residues as well as by a bridging hydroxide ion, a terminal water molecule, and at 4 degrees C, a bridging acetate ion, which is replaced at -160 degrees C with a bridging water molecule. Comparison of the results for two crystal forms demonstrates overall conservation and relative orientation of the domain structures. The most prominent structural differences identified between the two crystal forms is in an altered side chain conformation for Leu 110 at the active site cavity. We suggest that this residue serves as one component of a hydrophobic gate controlling access of substrates to and products from the active site. The leucine gate may be responsible for the effect of the B protein component on the reactivity of the reduced hydroxylase with dioxygen. A potential reductase binding site has been assigned based on an analysis of crystal packing in the two forms and corroborated by inhibition studies with a synthetic peptide corresponding to the proposed docking position.
About this StructureAbout this Structure
1MTY is a Protein complex structure of sequences from Methylococcus capsulatus with as ligand. Active as Methane monooxygenase, with EC number 1.14.13.25 Known structural/functional Site: . Full crystallographic information is available from OCA.
ReferenceReference
Crystal structures of the methane monooxygenase hydroxylase from Methylococcus capsulatus (Bath): implications for substrate gating and component interactions., Rosenzweig AC, Brandstetter H, Whittington DA, Nordlund P, Lippard SJ, Frederick CA, Proteins. 1997 Oct;29(2):141-52. PMID:9329079
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