title: CYP116B5: a new class VII catalytically self-sufficient cytochrome P450 from Acinetobacter radioresistens that enables growth on alkanes.
abstract: A gene coding for a class VII cytochrome P450 monooxygenase (CYP116B5) was identified from Acinetobacter radioresistens S13 growing on media with medium (C14, C16) and long (C24, C36) chain alkanes as the sole energy source. Phylogenetic analysis of its N- and C-terminal domains suggests an evolutionary model involving a plasmid-mediated horizontal gene transfer from the donor Rhodococcus jostii RHA1 to the receiving A. radioresistens S13. This event was followed by fusion and integration of the new gene in A. radioresistens chromosome. Heterologous expression of CYP116B5 in Escherichia coli BL21, together with the A. radioresistens Baeyer-Villiger monooxygenase, allowed the recombinant bacteria to grow on long- and medium-chain alkanes, showing that CYP116B5 is involved in the first step of terminal oxidation of medium-chain alkanes overlapping AlkB and in the first step of sub-terminal oxidation of long-chain alkanes. It was also demonstrated that CYP116B5 is a self-sufficient cytochrome P450 consisting of a heme domain (aa 1-392) involved in the oxidation step of n-alkanes degradation, and its reductase domain (aa 444-758) comprising the NADPH-, FMN- and [2Fe2S]-binding sites. To our knowledge, CYP116B5 is the first member of this class to have its natural substrate and function identified.
authors.affiliation: Department of Life Sciences and Systems Biology, University of Torino, via Accademia Albertina 13, Torino, 10123, Italy.
authors.forename: Daniela
authors.initials: D
authors.lastname: Minerdi
authors.forename: Sheila J
authors.initials: SJ
authors.lastname: Sadeghi
authors.forename: Giovanna
authors.initials: G
authors.lastname: Di Nardo
authors.forename: Francesco
authors.initials: F
authors.lastname: Rua
authors.forename: Silvia
authors.initials: S
authors.lastname: Castrignanò
authors.forename: Paola
authors.initials: P
authors.lastname: Allegra
authors.forename: Gianfranco
authors.initials: G
authors.lastname: Gilardi
mesh_terms: D000150:Acinetobacter / Q000201:enzymology* / Q000235:genetics* / Q000254:growth & development; D000473:Alkanes / Q000378:metabolism*; D000595:Amino Acid Sequence; D001665:Binding Sites; D055162:Biocatalysis; D005075:Biological Evolution; D003577:Cytochrome P-450 Enzyme System / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics / Q000254:growth & development; D019143:Evolution, Molecular; D022761:Gene Transfer, Horizontal; D006418:Heme / Q000737:chemistry; D007558:Italy; D008969:Molecular Sequence Data; D009249:NADP / Q000378:metabolism; D010084:Oxidation-Reduction; D010802:Phylogeny; D011994:Recombinant Proteins / Q000378:metabolism; D012240:Rhodococcus / Q000235:genetics; D016415:Sequence Alignment; D012988:Soil Microbiology
chemical_list: D000473:Alkanes; D011994:Recombinant Proteins; D006418:Heme; D009249:NADP; D003577:Cytochrome P-450 Enzyme System