PDBsum entry 1gem

Oxidoreductase

PDB id: 1gem

Contents

Protein chain

405 a.a. *

Ligands

HEM-NBN

Waters ×162

* Residue conservation analysis

PDB id:

1gem

Name:

Oxidoreductase

Title:

Structural characterization of n-butyl-isocyanide complexes of cytochromes p450nor and p450cam

Structure:

Cytochrome p450cam. Chain: a. Engineered: yes

Source:

Pseudomonas putida. Organism_taxid: 303. Expressed in: escherichia coli. Expression_system_taxid: 562.

Resolution:

2.00Å R-factor: 0.179 R-free: 0.225

Authors:

D.-S.Lee,S.-Y.Park,K.Yamane,Y.Shiro

Key ref:

D.S.Lee et al. (2001). Structural characterization of n-butyl-isocyanide complexes of cytochromes P450nor and P450cam. Biochemistry, 40, 2669-2677. PubMed id: 11258878 DOI: 10.1021/bi002225s

Date:

13-Nov-00 Release date: 06-Dec-00

Protein chain

P00183  (CPXA_PSEPU) -  Camphor 5-monooxygenase from Pseudomonas putida

Seq: 415 a.a.

Struc: 405 a.a.

Enzyme reactions

• Enzyme class: E.C.1.14.15.1 - camphor 5-monooxygenase.
• Reaction: 2 reduced [2Fe-2S]-[putidaredoxin] + (1R,4R)-camphor + O2 + 2 H⁺ = (1R,4R,5R)-5-hydroxycamphor + 2 oxidized [2Fe-2S]-[putidaredoxin] + H2O
• Cofactor: Heme-thiolate

Molecule diagrams generated from .mol files obtained from the KEGG ftp site

Key reference

DOI no: 10.1021/bi002225s

Biochemistry 40:2669-2677 (2001)

PubMed id: 11258878

Structural characterization of n-butyl-isocyanide complexes of cytochromes P450nor and P450cam.

D.S.Lee, S.Y.Park, K.Yamane, E.Obayashi, H.Hori, Y.Shiro.

ABSTRACT

Alkyl-isocyanides are able to bind to both ferric and ferrous iron of the heme in cytochrome P450, and the resulting complexes exhibit characteristic optical absorption spectra. While the ferric complex gives a single Soret band at 430 nm, the ferrous complex shows double Soret bands at 430 and 450 nm. The ratio of intensities of the double Soret bands in the ferrous isocyanide complex of P450 varies, as a function of pH, ionic strength, and the origin of the enzyme. To understand the structural origin of these characteristic spectral features, we examined the crystallographic and spectrophotometric properties of the isocyanide complexes of Pseudomonas putida cytochrome P450cam and Fusarium oxysporum cytochorme P450nor, since ferrous isocyanide complex of P450cam gives a single Soret band at 453 nm, while that of P450nor gives one at 427 nm. Corresponding to the optical spectra, we observed C-N stretching of a ferrous iron-bound isocyanide at 2145 and 2116 cm(-1) for P450nor and P450cam, respectively. The crystal structures of the ferric and ferrous n-butyl isocyanide complexes of P450cam and P450nor were determined. The coordination structure of the fifth Cys thiolate was indistinguishable for the two P450s, but the coordination geometry of the isocyanide was different for the case of P450cam [d(Fe-C) = 1.86 A, angleFe-C-N = 159 degrees ] versus P450nor [d(Fe-C) = 1.85 A, angleFe-C-N = 175 degrees ]. Another difference in the structures was the chemical environment of the heme pocket. In the case of P450cam, the iron-bound isocyanide is surrounded by some hydrophobic side chains, while, for P450nor, it is surrounded by polar groups including several water molecules. On the basis of these observations, we proposed that the steric factors and/or the polarity of the environment surrounding the iron-bound isocyanide significantly effect on the resonance structure of the heme(Fe)-isocyanide moiety and that differences in these two factors are responsible for the spectral characteristics for P450s.