1RE9

CRYSTAL STRUCTURE OF CYTOCHROME P450-CAM WITH A FLUORESCENT PROBE D-8-AD (ADAMANTANE-1-CARBOXYLIC ACID-5-DIMETHYLAMINO-NAPHTHALENE-1-SULFONYLAMINO-OCTYL-AMIDE)

Summary for 1RE9

• Entry DOI: 10.2210/pdb1re9/pdb
• Related: 1LWL
• Descriptor: Cytochrome P450-cam, POTASSIUM ION, PROTOPORPHYRIN IX CONTAINING FE, ... (6 entities in total)
• Functional Keywords: monooxygenase, conformational states, substrate-linked sensitizers, substrate-binding, dansyl, adamantane, adamantane-1-carboxylic acid, 4-(5-dimethylamino-naphthalene-1-sulfonylamino)-octyl]-amide, channel, oxidoreductase
• Biological source: Pseudomonas putida
• Cellular location: Cytoplasm (By similarity): P00183
• Total number of polymer chains: 1
• Total formula weight: 47970.44

Authors

Hays, A.-M.A.,Dunn, A.R.,Gray, H.B.,Stout, C.D.,Goodin, D.B. (deposition date: 2003-11-06, release date: 2004-11-16, Last modification date: 2023-08-23)

Primary citation

Hays, A.M.,Dunn, A.R.,Chiu, R.,Gray, H.B.,Stout, C.D.,Goodin, D.B.
Conformational states of cytochrome P450cam revealed by trapping of synthetic molecular wires.
J.Mol.Biol., 344:455-469, 2004

PubMed Abstract: Members of the ubiquitous cytochrome P450 family catalyze a vast range of biologically significant reactions in mammals, plants, fungi, and bacteria. Some P450s display a remarkable promiscuity in substrate recognition, while others are very specific with respect to substrate binding or regio and stereo-selective catalysis. Recent results have suggested that conformational flexibility in the substrate access channel of many P450s may play an important role in controlling these effects. Here, we report the X-ray crystal structures at 1.8A and 1.5A of cytochrome P450cam complexed with two synthetic molecular wires, D-4-Ad and D-8-Ad, consisting of a dansyl fluorophore linked to an adamantyl substrate analog via an alpha,omega-diaminoalkane chain of varying length. Both wires bind with the adamantyl moiety in similar positions at the camphor-binding site. However, each wire induces a distinct conformational response in the protein that differs from the camphor-bound structure. The changes involve significant movements of the F, G, and I helices, allowing the substrate access channel to adapt to the variable length of the probe. Wire-induced opening of the substrate channel also alters the I helix bulge and Thr252 at the active site with binding of water that has been proposed to assist in peroxy bond cleavage. The structures suggest that the coupling of substrate-induced conformational changes to active-site residues may be different in P450cam and recently described mammalian P450 structures. The wire-induced changes may be representative of the conformational intermediates that must exist transiently during substrate entry and product egress, providing a view of how substrates enter the deeply buried active site. They also support observed examples of conformational plasticity that are believed be responsible for the promiscuity of drug metabolizing P450s. Observation of such large changes in P450cam suggests that substrate channel plasticity is a general property inherent to all P450 structures.

PubMed: 15522298
DOI: 10.1016/j.jmb.2004.09.046

Experimental method

X-RAY DIFFRACTION (1.45 Å)