Wei Zhang - Solution NMR structure of putidaredoxin-cytochrome P450cam complex via a combined residual dipolar coupling-spin labeling approach suggests a role for Trp106 of putidaredoxin in complex formation.

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      Publication Details (including relevant citation   information):

      J Mol Biol. 2008 Dec   12;384(2):349-63. Epub 2008 Sep 20.

      Abstract:

      The 58-kDa complex formed between the [2Fe-2S] ferredoxin,   putidaredoxin (Pdx), and cytochrome P450cam (CYP101) from the   bacterium Pseudomonas putida has been investigated by   high-resolution solution NMR spectroscopy. Pdx serves as both the   physiological reductant and effector for CYP101 in the enzymatic   reaction involving conversion of substrate camphor to   5-exo-hydroxycamphor. In order to obtain an experimental   structure for the oxidized Pdx-CYP101 complex, a combined   approach using orientational data on the two proteins derived   from residual dipolar couplings and distance restraints from   site-specific spin labeling of Pdx has been applied. Spectral   changes for residues in and near the paramagnetic metal cluster   region of Pdx in complex with CYP101 have also been mapped for   the first time using (15)N and (13)C NMR spectroscopy, leading to   direct identification of the residues strongly affected by CYP101   binding. The new NMR structure of the Pdx-CYP101 complex agrees   well with results from previous mutagenesis and biophysical   studies involving residues at the binding interface such as   formation of a salt bridge between Asp38 of Pdx and Arg112 of   CYP101, while at the same time identifying key features different   from those of earlier modeling studies. Analysis of the binding   interface of the complex reveals that the side chain of Trp106,   the C-terminal residue of Pdx and critical for binding to CYP101,   is located across from the heme-binding loop of CYP101 and forms   non-polar contacts with several residues in the vicinity of the   heme group on CYP101, pointing to a potentially important role in   complex formation

      Address (URL): http://www.ncbi.nlm.nih.gov/pubmed/18835276