1xvb: Difference between revisions
New page: left|200px<br /><applet load="1xvb" size="450" color="white" frame="true" align="right" spinBox="true" caption="1xvb, resolution 1.80Å" /> '''soluble methane mono... |
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[[Image:1xvb.gif|left|200px]]<br /><applet load="1xvb" size=" | [[Image:1xvb.gif|left|200px]]<br /><applet load="1xvb" size="350" color="white" frame="true" align="right" spinBox="true" | ||
caption="1xvb, resolution 1.80Å" /> | caption="1xvb, resolution 1.80Å" /> | ||
'''soluble methane monooxygenase hydroxylase: 6-bromohexanol soaked structure'''<br /> | '''soluble methane monooxygenase hydroxylase: 6-bromohexanol soaked structure'''<br /> | ||
==Overview== | ==Overview== | ||
The soluble methane monooxygenase hydroxylase (MMOH) alpha-subunit | The soluble methane monooxygenase hydroxylase (MMOH) alpha-subunit contains a series of cavities that delineate the route of substrate entrance to and product egress from the buried carboxylate-bridged diiron center. The presence of discrete cavities is a major structural difference between MMOH, which can hydroxylate methane, and toluene/o-xylene monooxygenase hydroxylase (ToMOH), which cannot. To understand better the functions of the cavities and to investigate how an enzyme designed for methane hydroxylation can also accommodate larger substrates such as octane, methylcubane, and trans-1-methyl-2-phenylcyclopropane, MMOH crystals were soaked with an assortment of different alcohols and their X-ray structures were solved to 1.8-2.4 A resolution. The product analogues localize to cavities 1-3 and delineate a path of product exit and/or substrate entrance from the active site to the surface of the protein. The binding of the alcohols to a position bridging the two iron atoms in cavity 1 extends and validates previous crystallographic, spectroscopic, and computational work indicating this site to be where substrates are hydroxylated and products form. The presence of these alcohols induces perturbations in the amino acid side-chain gates linking pairs of cavities, allowing for the formation of a channel similar to one observed in ToMOH. Upon binding of 6-bromohexan-1-ol, the pi helix formed by residues 202-211 in helix E of the alpha-subunit is extended through residue 216, changing the orientations of several amino acid residues in the active site cavity. This remarkable secondary structure rearrangement in the four-helix bundle has several mechanistic implications for substrate accommodation and the function of the effector protein, MMOB. | ||
==About this Structure== | ==About this Structure== | ||
1XVB is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Methylococcus_capsulatus Methylococcus capsulatus] with FE, CA, BHL, BBX, 3BR and BBU as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Methane_monooxygenase Methane monooxygenase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.14.13.25 1.14.13.25] Full crystallographic information is available from [http:// | 1XVB is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Methylococcus_capsulatus Methylococcus capsulatus] with <scene name='pdbligand=FE:'>FE</scene>, <scene name='pdbligand=CA:'>CA</scene>, <scene name='pdbligand=BHL:'>BHL</scene>, <scene name='pdbligand=BBX:'>BBX</scene>, <scene name='pdbligand=3BR:'>3BR</scene> and <scene name='pdbligand=BBU:'>BBU</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Methane_monooxygenase Methane monooxygenase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.14.13.25 1.14.13.25] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1XVB OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: Methylococcus capsulatus]] | [[Category: Methylococcus capsulatus]] | ||
[[Category: Protein complex]] | [[Category: Protein complex]] | ||
[[Category: Lippard, S | [[Category: Lippard, S J.]] | ||
[[Category: Sazinsky, M | [[Category: Sazinsky, M H.]] | ||
[[Category: 3BR]] | [[Category: 3BR]] | ||
[[Category: BBU]] | [[Category: BBU]] | ||
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[[Category: products]] | [[Category: products]] | ||
''Page seeded by [http:// | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:59:01 2008'' | ||
Revision as of 16:59, 21 February 2008
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soluble methane monooxygenase hydroxylase: 6-bromohexanol soaked structure
OverviewOverview
The soluble methane monooxygenase hydroxylase (MMOH) alpha-subunit contains a series of cavities that delineate the route of substrate entrance to and product egress from the buried carboxylate-bridged diiron center. The presence of discrete cavities is a major structural difference between MMOH, which can hydroxylate methane, and toluene/o-xylene monooxygenase hydroxylase (ToMOH), which cannot. To understand better the functions of the cavities and to investigate how an enzyme designed for methane hydroxylation can also accommodate larger substrates such as octane, methylcubane, and trans-1-methyl-2-phenylcyclopropane, MMOH crystals were soaked with an assortment of different alcohols and their X-ray structures were solved to 1.8-2.4 A resolution. The product analogues localize to cavities 1-3 and delineate a path of product exit and/or substrate entrance from the active site to the surface of the protein. The binding of the alcohols to a position bridging the two iron atoms in cavity 1 extends and validates previous crystallographic, spectroscopic, and computational work indicating this site to be where substrates are hydroxylated and products form. The presence of these alcohols induces perturbations in the amino acid side-chain gates linking pairs of cavities, allowing for the formation of a channel similar to one observed in ToMOH. Upon binding of 6-bromohexan-1-ol, the pi helix formed by residues 202-211 in helix E of the alpha-subunit is extended through residue 216, changing the orientations of several amino acid residues in the active site cavity. This remarkable secondary structure rearrangement in the four-helix bundle has several mechanistic implications for substrate accommodation and the function of the effector protein, MMOB.
About this StructureAbout this Structure
1XVB is a Protein complex structure of sequences from Methylococcus capsulatus with , , , , and as ligands. Active as Methane monooxygenase, with EC number 1.14.13.25 Full crystallographic information is available from OCA.
ReferenceReference
Product bound structures of the soluble methane monooxygenase hydroxylase from Methylococcus capsulatus (Bath): protein motion in the alpha-subunit., Sazinsky MH, Lippard SJ, J Am Chem Soc. 2005 Apr 27;127(16):5814-25. PMID:15839679
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