Modeling the interfacial interactions between CrtS and CrtR from Xanthophyllomyces dendrorhous , a P450 system involved in astaxanthin production.
Xanthophyllomyces dendrorhous  is a natural source of astaxanthin, a carotenoid widely used in the food industry. In this yeast, astaxanthin is synthesized from β-carotene by a cytochrome P450, CrtS, which depends on CrtR, the four-domain cytochrome P450 reductase (CPR). Although  Saccharomyces cerevisiae  has an endogenous CPR (ScCPR), expression of CrtS does not result in astaxanthin production unless it is coexpressed with CrtR. Assuming that CrtS could interact with the FMN-binding domain of either CrtR or ScCPR (XdFMNbd and ScFMNbd, respectively), the aim of this work was to identify possible interaction differences between these alternative complexes by protein modeling and short molecular dynamics simulations. Considering the recently proposed membrane orientation of a mammalian P450, our CrtS-CrtR model predicts that both N-terminal ends stand adjacent to the membrane plane, allowing their anchoring. Compared with the possible interface between CrtS and both FMNbd, the Xanthophyllomyces system appears to be stabilized by more saline bridges.
Centro de Biotecnología y Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile, Las Palmeras 3425, Casilla 653, Santiago, Chile.
Jennifer
J
Alcaíno
Matías
M
Fuentealba
Ricardo
R
Cabrera
Marcelo
M
Baeza
Víctor
V
Cifuentes
D001487:Basidiomycota / Q000201:enzymology* / Q000235:genetics; D001665:Binding Sites; D003577:Cytochrome P-450 Enzyme System / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D005486:Flavin Mononucleotide / Q000378:metabolism; D008958:Models, Molecular; D009251:NADPH-Ferrihemoprotein Reductase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017433:Protein Structure, Secondary; D024341:Xanthophylls / Q000096:biosynthesis; D019207:beta Carotene / Q000378:metabolism
D024341:Xanthophylls; D019207:beta Carotene; D005486:Flavin Mononucleotide; C005948:astaxanthine; D003577:Cytochrome P-450 Enzyme System; D009251:NADPH-Ferrihemoprotein Reductase