1phc
CRYSTAL STRUCTURE OF SUBSTRATE-FREE PSEUDOMONAS PUTIDA CYTOCHROME P450CRYSTAL STRUCTURE OF SUBSTRATE-FREE PSEUDOMONAS PUTIDA CYTOCHROME P450
Structural highlights
Function[CPXA_PSEPU] Involved in a camphor oxidation system. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe 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. Crystal structure of substrate-free Pseudomonas putida cytochrome P-450.,Poulos TL, Finzel BC, Howard AJ Biochemistry. 1986 Sep 9;25(18):5314-22. PMID:3768350[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences |
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