title: Identification of productive and futile encounters in an electron transfer protein complex.
abstract: Well-defined, stereospecific states in protein complexes are often in exchange with an ensemble of more dynamic orientations: the encounter states. The structure of the stereospecific complex between cytochrome P450cam and putidaredoxin was solved recently by X-ray diffraction as well as paramagnetic NMR spectroscopy. Other than the stereospecific complex, the NMR data clearly show the presence of additional states in the complex in solution. In these encounter states, populated for a small percentage of the time, putidaredoxin assumes multiple orientations and samples a large part of the surface of cytochrome P450cam. To characterize the nature of the encounter states, an extensive paramagnetic NMR dataset has been analyzed using the Maximum Occurrence of Regions methodology. The analysis reveals the location and maximal spatial extent of the additional states needed to fully explain the NMR data. Under the assumption of sparsity of the size of the conformational ensemble, several minor states can be located quite precisely. The distribution of these minor states correlates with the electrostatic potential map around cytochrome P450cam. Whereas some minor states are on isolated positively charged patches, others are connected to the stereospecific site via positively charged paths. The existence of electrostatically favorable pathways between the stereospecific interaction site and the different minor states or lack thereof suggests a means to discriminate between productive and futile encounter states.
authors.affiliation: Magnetic Resonance Center (CERM), University of Florence, 50019 Sesto Fiorentino, Italy.|Interuniversity Consortium for Magnetic Resonance of Metallo Proteins (CIRMMP), 50019 Sesto Fiorentino, Italy.|Department of Chemistry, University of Florence, 50019 Sesto Fiorentino, Italy.
authors.forename: Witold
authors.initials: W
authors.lastname: Andrałojć
authors.affiliation: Leiden Institute of Chemistry, Leiden University, 2333 CC Leiden, The Netherlands.
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Hiruma
authors.affiliation: Leiden Institute of Chemistry, Leiden University, 2333 CC Leiden, The Netherlands.
authors.forename: Wei-Min
authors.initials: WM
authors.lastname: Liu
authors.affiliation: Magnetic Resonance Center (CERM), University of Florence, 50019 Sesto Fiorentino, Italy.|Interuniversity Consortium for Magnetic Resonance of Metallo Proteins (CIRMMP), 50019 Sesto Fiorentino, Italy.
authors.forename: Enrico
authors.initials: E
authors.lastname: Ravera
authors.affiliation: Department of Chemistry, Graduate School of Science, Osaka University, Osaka 560-0043, Japan.|RIKEN SPring-8 Center, Hyogo 679-5148, Japan.
authors.forename: Masaki
authors.initials: M
authors.lastname: Nojiri
authors.affiliation: Magnetic Resonance Center (CERM), University of Florence, 50019 Sesto Fiorentino, Italy.|Interuniversity Consortium for Magnetic Resonance of Metallo Proteins (CIRMMP), 50019 Sesto Fiorentino, Italy.|Department of Chemistry, University of Florence, 50019 Sesto Fiorentino, Italy.
authors.forename: Giacomo
authors.initials: G
authors.lastname: Parigi
authors.affiliation: Magnetic Resonance Center (CERM), University of Florence, 50019 Sesto Fiorentino, Italy; luchinat@cerm.unifi.it m.ubbink@chem.leidenuniv.nl.|Interuniversity Consortium for Magnetic Resonance of Metallo Proteins (CIRMMP), 50019 Sesto Fiorentino, Italy.|Department of Chemistry, University of Florence, 50019 Sesto Fiorentino, Italy.
authors.forename: Claudio
authors.initials: C
authors.lastname: Luchinat
authors.affiliation: Leiden Institute of Chemistry, Leiden University, 2333 CC Leiden, The Netherlands; luchinat@cerm.unifi.it m.ubbink@chem.leidenuniv.nl.
authors.forename: Marcellus
authors.identifier: 0000-0002-2615-6914
authors.initials: M
authors.lastname: Ubbink
mesh_terms: D019475:Camphor 5-Monooxygenase / Q000737:chemistry* / Q000378:metabolism; D018360:Crystallography, X-Ray; D004579:Electron Transport; D005288:Ferredoxins / Q000737:chemistry* / Q000378:metabolism; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy; D046912:Multiprotein Complexes / Q000737:chemistry* / Q000378:metabolism; D016297:Mutagenesis, Site-Directed; D011485:Protein Binding; D011487:Protein Conformation; D014961:X-Ray Diffraction
chemical_list: D005288:Ferredoxins; D046912:Multiprotein Complexes; C100137:putidaredoxin; D019475:Camphor 5-Monooxygenase
keywords: cytochrome P450cam; encounter complex; maximum occurrence; paramagnetic NMR; putidaredoxin