1GEB
X-RAY CRYSTAL STRUCTURE AND CATALYTIC PROPERTIES OF THR252ILE MUTANT OF CYTOCHROME P450CAM
Summary for 1GEB
| Entry DOI | 10.2210/pdb1geb/pdb |
| Descriptor | CYTOCHROME P450-CAM, PROTOPORPHYRIN IX CONTAINING FE, CAMPHOR, ... (4 entities in total) |
| Functional Keywords | cytochrome p450cam, monooxygenase, electron transport |
| Biological source | Pseudomonas putida |
| Total number of polymer chains | 1 |
| Total formula weight | 47500.85 |
| Authors | Hishiki, T.,Shimada, H.,Nagano, S.,Park, S.-Y.,Ishimura, Y. (deposition date: 2000-11-01, release date: 2000-11-15, Last modification date: 2023-10-25) |
| Primary citation | Hishiki, T.,Shimada, H.,Nagano, S.,Egawa, T.,Kanamori, Y.,Makino, R.,Park, S.Y.,Adachi, S.,Shiro, Y.,Ishimura, Y. X-ray crystal structure and catalytic properties of Thr252Ile mutant of cytochrome P450cam: roles of Thr252 and water in the active center. J.Biochem., 128:965-974, 2000 Cited by PubMed Abstract: The structure-function relationship in cytochrome P450cam monooxygenase was studied by employing its active site mutant Thr252Ile. X-ray crystallographic analyses of the ferric d-camphor-bound form of the mutant revealed that the mutation caused a structural change in the active site giving an enlarged oxygen-binding pocket that did not contain any hydrophilic group such as the OH group of Thr and H(2)O. The enzyme showed a low monooxygenase activity of ca. 1/10 of the activity of the wild-type enzyme. Kinetic analyses of each catalytic step revealed that the rate of proton-coupled reduction of the oxygenated intermediate of the enzyme, a ternary complex of dioxygen and d-camphor with the ferrous enzyme, decreased to about 1/30 of that of the wild-type enzyme, while the rates of other catalytic steps including the reduction of the ferric d-camphor-bound form by reduced putidaredoxin did not change significantly. These results indicated that a hydrophilic group(s) such as water and/or hydroxyl group in the active site is prerequisite to a proton supply for the reduction of the oxygenated intermediate, thereby giving support for the operation of a proton transfer network composed of Thr252, Asp251, and two other amino acids and water proposed by previous investigators. PubMed: 11098139DOI: 10.1093/oxfordjournals.jbchem.a022848 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (2.03 Å) |
Structure validation
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