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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
18
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pubmed:dateCreated |
1986-12-15
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pubmed:abstractText |
The crystal structure of Pseudomonas putida cytochrome P-450cam in the substrate-free form has been refined at 2.20-A resolution and compared to the substrate-bound form of the enzyme. In the absence of the substrate camphor, the P-450cam heme iron atom is hexacoordinate with the sulfur atom of Cys-357 providing one axial heme ligand and a water molecule or hydroxide ion providing the other axial ligand. A network of hydrogen-bonded solvent molecules occupies the substrate pocket in addition to the iron-linked aqua ligand. When a camphor molecule binds, the active site waters including the aqua ligand are displaced, resulting in a pentacoordinate high-spin heme iron atom. Analysis of the Fno camphor - F camphor difference Fourier and a quantitative comparison of the two refined structures reveal that no detectable conformational change results from camphor binding other than a small repositioning of a phenylalanine side chain that contacts the camphor molecule. However, large decreases in the mean temperature factors of three separate segments of the protein centered on Tyr-96, Thr-185, and Asp-251 result from camphor binding. This indicates that camphor binding decreases the flexibility in these three regions of the P-450cam molecule without altering the mean position of the atoms involved.
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pubmed:grant | |
pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical | |
pubmed:status |
MEDLINE
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pubmed:month |
Sep
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pubmed:issn |
0006-2960
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:day |
9
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pubmed:volume |
25
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
5314-22
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pubmed:dateRevised |
2007-11-14
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pubmed:meshHeading |
pubmed-meshheading:3768350-Crystallization,
pubmed-meshheading:3768350-Cytochrome P-450 Enzyme System,
pubmed-meshheading:3768350-Dithiothreitol,
pubmed-meshheading:3768350-Models, Molecular,
pubmed-meshheading:3768350-Protein Conformation,
pubmed-meshheading:3768350-Pseudomonas,
pubmed-meshheading:3768350-X-Ray Diffraction
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pubmed:year |
1986
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pubmed:articleTitle |
Crystal structure of substrate-free Pseudomonas putida cytochrome P-450.
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pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.
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