2jho

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==Overview==
==Overview==
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X-ray absorption spectroscopy is exquisitely sensitive to the coordination, geometry of an absorbing atom and therefore allows bond distances and, angles of the surrounding atomic cluster to be measured with atomic, resolution. By contrast, the accuracy and resolution of metalloprotein, active sites obtainable from x-ray crystallography are often insufficient, to analyze the electronic properties of the metals that are essential for, their biological functions. Here, we demonstrate that the combination of, both methods on the same metalloprotein single crystal yields a structural, model of the protein with exceptional active-site resolution. To this end, we have collected an x-ray diffraction data set to 1.4-A resolution and Fe, K-edge polarized x-ray absorption near edge structure (XANES) spectra on, the same cyanomet sperm whale myoglobin crystal. The XANES spectra were, quantitatively analyzed by using a method based on the multiple scattering, approach, which yielded Fe-heme structural parameters with, +/-(0.02-0.07)-A accuracy on the atomic distances and +/-7 degrees on the, Fe-CN angle. These XANES-derived parameters were subsequently used as, restraints in the crystal structure refinement. By combining XANES and, x-ray diffraction, we have obtained an cyanomet sperm whale myoglobin, structural model with a higher precision of the bond lengths and angles at, the active site than would have been possible with crystallographic, analysis alone.
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X-ray absorption spectroscopy is exquisitely sensitive to the coordination geometry of an absorbing atom and therefore allows bond distances and angles of the surrounding atomic cluster to be measured with atomic resolution. By contrast, the accuracy and resolution of metalloprotein active sites obtainable from x-ray crystallography are often insufficient to analyze the electronic properties of the metals that are essential for their biological functions. Here, we demonstrate that the combination of both methods on the same metalloprotein single crystal yields a structural model of the protein with exceptional active-site resolution. To this end, we have collected an x-ray diffraction data set to 1.4-A resolution and Fe K-edge polarized x-ray absorption near edge structure (XANES) spectra on the same cyanomet sperm whale myoglobin crystal. The XANES spectra were quantitatively analyzed by using a method based on the multiple scattering approach, which yielded Fe-heme structural parameters with +/-(0.02-0.07)-A accuracy on the atomic distances and +/-7 degrees on the Fe-CN angle. These XANES-derived parameters were subsequently used as restraints in the crystal structure refinement. By combining XANES and x-ray diffraction, we have obtained an cyanomet sperm whale myoglobin structural model with a higher precision of the bond lengths and angles at the active site than would have been possible with crystallographic analysis alone.
==About this Structure==
==About this Structure==
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[[Category: Benfatto, M.]]
[[Category: Benfatto, M.]]
[[Category: Cianci, M.]]
[[Category: Cianci, M.]]
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[[Category: Hasnain, S.S.]]
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[[Category: Hasnain, S S.]]
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[[Category: Longa, S.Della.]]
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[[Category: Longa, S Della.]]
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[[Category: Nienhaus, G.U.]]
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[[Category: Nienhaus, G U.]]
[[Category: Nienhaus, K.]]
[[Category: Nienhaus, K.]]
[[Category: Savino, C.]]
[[Category: Savino, C.]]
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[[Category: Strange, R.W.]]
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[[Category: Strange, R W.]]
[[Category: Vallone, B.]]
[[Category: Vallone, B.]]
[[Category: CYN]]
[[Category: CYN]]
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[[Category: transport]]
[[Category: transport]]
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''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Feb 3 10:46:00 2008''
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''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 18:03:26 2008''

Revision as of 16:03, 21 February 2008


2jho, resolution 1.40Å

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CYANOMET SPERM WHALE MYOGLOBIN AT 1.4A RESOLUTION

Overview

X-ray absorption spectroscopy is exquisitely sensitive to the coordination geometry of an absorbing atom and therefore allows bond distances and angles of the surrounding atomic cluster to be measured with atomic resolution. By contrast, the accuracy and resolution of metalloprotein active sites obtainable from x-ray crystallography are often insufficient to analyze the electronic properties of the metals that are essential for their biological functions. Here, we demonstrate that the combination of both methods on the same metalloprotein single crystal yields a structural model of the protein with exceptional active-site resolution. To this end, we have collected an x-ray diffraction data set to 1.4-A resolution and Fe K-edge polarized x-ray absorption near edge structure (XANES) spectra on the same cyanomet sperm whale myoglobin crystal. The XANES spectra were quantitatively analyzed by using a method based on the multiple scattering approach, which yielded Fe-heme structural parameters with +/-(0.02-0.07)-A accuracy on the atomic distances and +/-7 degrees on the Fe-CN angle. These XANES-derived parameters were subsequently used as restraints in the crystal structure refinement. By combining XANES and x-ray diffraction, we have obtained an cyanomet sperm whale myoglobin structural model with a higher precision of the bond lengths and angles at the active site than would have been possible with crystallographic analysis alone.

About this Structure

2JHO is a Single protein structure of sequence from [1] with , , and as ligands. Known structural/functional Sites: , , , and . Full crystallographic information is available from OCA.

Reference

X-ray structure analysis of a metalloprotein with enhanced active-site resolution using in situ x-ray absorption near edge structure spectroscopy., Arcovito A, Benfatto M, Cianci M, Hasnain SS, Nienhaus K, Nienhaus GU, Savino C, Strange RW, Vallone B, Della Longa S, Proc Natl Acad Sci U S A. 2007 Apr 10;104(15):6211-6. Epub 2007 Apr 2. PMID:17404234

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