The Structure of the Cytochrome P450cam-Putidaredoxin Complex Determined by Paramagnetic NMR Spectroscopy and Crystallography.
 

The Structure of the Cytochrome P450cam-Putidaredoxin Complex Determined by Paramagnetic NMR Spectroscopy and Crystallography.

The Structure of the Cytochrome P450cam-Putidaredoxin Complex Determined by Paramagnetic NMR Spectroscopy and Crystallography.

J Mol Biol. 2013 Jul 12;

Authors: Hiruma Y, Hass MA, Kikui Y, Liu WM, Olmez B, Skinner SP, Blok A, Kloosterman A, Koteishi H, Lohr F, Schwalbe H, Nojiri M, Ubbink M

Abstract
Cytochrome P450cam catalyzes the hydroxylation of camphor in a complex process involving two electron transfers from the iron sulfur protein putidaredoxin. The enzymatic control of the successive steps of catalysis is critical for a highly efficient reaction. The injection of the successive electrons is part of the control system. To understand the molecular interactions between putidaredoxin and cytochrome P450cam the structure of the complex was determined both in solution and in the crystal state. Paramagnetic NMR spectroscopy using lanthanide tags yielded 446 structural restraints that were used to determine the solution structure. An ensemble of 10 structures with an RMSD of 1.3 Å was obtained. The crystal structure of the complex was solved, showing a position of putidaredoxin that is identical to the one in the solution structure. The NMR data further demonstrate the presence of a minor state or set of states of the complex in solution, which is attributed to the presence of an encounter complex. The structure of the major state shows a small binding interface and a metal-to-metal distance of 16 Å, with two pathways that provide strong electronic coupling of the redox centers. The interpretation of these results is discussed in the context of electron transfer. The structure indicates that the electron transfer rate can be much faster than the reported value, suggesting that the process may be gated.


PMID: 23856620 [PubMed - as supplied by publisher]



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