title: Molecular characterization of a class I P450 electron transfer system from Novosphingobium aromaticivorans DSM12444.
abstract: Cytochrome P450 (CYP) enzymes of the CYP101 and CYP111 families from the oligotrophic bacterium Novosphingobium aromaticivorans DSM12444 are heme monooxygenases that receive electrons from NADH via Arx, a [2Fe-2S] ferredoxin, and ArR, a ferredoxin reductase. These systems show fast NADH turnovers (k(cat) = 39-91 s(-1)) that are efficiently coupled to product formation. The three-dimensional structures of ArR, Arx, and CYP101D1, which form a physiological class I P450 electron transfer chain, have been resolved by x-ray crystallography. The general structural features of these proteins are similar to their counterparts in other class I systems such as putidaredoxin reductase (PdR), putidaredoxin (Pdx), and CYP101A1 of the camphor hydroxylase system from Pseudomonas putida, and adrenodoxin (Adx) of the mitochondrial steroidogenic CYP11 and CYP24A1 systems. However, significant differences in the proposed protein-protein interaction surfaces of the ferredoxin reductase, ferredoxin, and P450 enzyme are found. There are regions of positive charge on the likely interaction face of ArR and CYP101D1 and a corresponding negatively charged area on the surface of Arx. The [2Fe-2S] cluster binding loop in Arx also has a neutral, hydrophobic patch on the surface. These surface characteristics are more in common with those of Adx than Pdx. The observed structural features are consistent with the ionic strength dependence of the activity.
authors.affiliation: Tianjin Key Laboratory of Protein Science, College of Life Sciences, Nankai University, Tianjin 300071, China.
authors.forename: Wen
authors.initials: W
authors.lastname: Yang
authors.affiliation: Department of Chemistry, Inorganic Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QR, United Kingdom. Electronic address: stephen.bell@chem.ox.ac.uk.
authors.forename: Stephen G
authors.initials: SG
authors.lastname: Bell
authors.affiliation: Laboratory of Structural Biology, Tsinghua University, Beijing 100084, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Wang
authors.affiliation: Tianjin Key Laboratory of Protein Science, College of Life Sciences, Nankai University, Tianjin 300071, China.
authors.forename: Weihong
authors.initials: W
authors.lastname: Zhou
authors.affiliation: Department of Chemistry, Inorganic Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QR, United Kingdom.
authors.forename: Nicola
authors.initials: N
authors.lastname: Hoskins
authors.affiliation: Department of Chemistry, Inorganic Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QR, United Kingdom.
authors.forename: Alison
authors.initials: A
authors.lastname: Dale
authors.affiliation: Tianjin Key Laboratory of Protein Science, College of Life Sciences, Nankai University, Tianjin 300071, China; Laboratory of Structural Biology, Tsinghua University, Beijing 100084, China. Electronic address: bartlam@nankai.edu.cn.
authors.forename: Mark
authors.initials: M
authors.lastname: Bartlam
authors.affiliation: Department of Chemistry, Inorganic Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QR, United Kingdom.
authors.forename: Luet-Lok
authors.initials: LL
authors.lastname: Wong
authors.affiliation: Tianjin Key Laboratory of Protein Science, College of Life Sciences, Nankai University, Tianjin 300071, China; Laboratory of Structural Biology, Tsinghua University, Beijing 100084, China.
authors.forename: Zihe
authors.initials: Z
authors.lastname: Rao
mesh_terms: D000325:Adrenodoxin / Q000737:chemistry; D001426:Bacterial Proteins / Q000737:chemistry*; D019475:Camphor 5-Monooxygenase / Q000737:chemistry*; D005287:Ferredoxin-NADP Reductase / Q000737:chemistry; D005288:Ferredoxins / Q000737:chemistry; D057927:Hydrophobic and Hydrophilic Interactions; D009249:NADP / Q000737:chemistry; D020836:Protein Structure, Quaternary; D017433:Protein Structure, Secondary; D042301:Sphingomonadaceae / Q000201:enzymology*; D040681:Structural Homology, Protein
chemical_list: D001426:Bacterial Proteins; D005288:Ferredoxins; D000325:Adrenodoxin; D009249:NADP; D019475:Camphor 5-Monooxygenase; D005287:Ferredoxin-NADP Reductase