Abstract
BackgroundCyanobacteria possess several cytochrome P450s, but very little is known about their catalytic functions. CYP110 genes unique to cyanaobacteria are widely distributed in heterocyst-forming cyanobacteria including nitrogen-fixing genera Nostoc and Anabaena. We screened the biocatalytic functions of all P450s from three cyanobacterial strains of genus Nostoc or Anabaena using a series of small molecules that contain flavonoids, sesquiterpenes, low-molecular-weight drugs, and other aromatic compounds.ResultsEscherichia coli cells carrying each P450 gene that was inserted into the pRED vector, containing the RhFRed reductase domain sequence from Rhodococcus sp. NCIMB 9784 P450RhF (CYP116B2), were co-cultured with substrates and products were identified when bioconversion reactions proceeded. Consequently, CYP110E1 of Nostoc sp. strain PCC 7120, located in close proximity to the first branch point in the phylogenetic tree of the CYP110 family, was found to be promiscuous for the substrate range mediating the biotransformation of various small molecules. Naringenin and (hydroxyl) flavanones were respectively converted to apigenin and (hydroxyl) flavones, by functioning as a flavone synthase. Such an activity is reported for the first time in prokaryotic P450s. Additionally, CYP110E1 biotransformed the notable sesquiterpene zerumbone, anti-inflammatory drugs ibuprofen and flurbiprofen (methylester forms), and some aryl compounds such as 1-methoxy and 1-ethoxy naphthalene to produce hydroxylated compounds that are difficult to synthesize chemically, including novel compounds.ConclusionWe elucidated that the CYP110E1 gene, C-terminally fused to the P450RhF RhFRed reductase domain sequence, is functionally expressed in E. coli to synthesize a robust monooxygenase, which shows promiscuous substrate specificity (affinity) for various small molecules, allowing the biosynthesis of not only flavones (from flavanones) but also a variety of hydroxyl-small molecules that may span pharmaceutical and nutraceutical industries.
Highlights
Cyanobacteria possess several cytochrome P450s, but very little is known about their catalytic functions
CYP110A1 is the first reported cyanobacterial P450 gene, which was present in a conserved 11.25-kb episomal element, and the encoded protein (CYP110A1) was hypothesized to be a fatty acid ω-hydroxylase, based on its substrate binding profile and amino acid sequence similarities to P450BM3 (CYP102A1) of Bacillus megaterium and the mammalian P450 family 4 fatty acid ω-hydroxylase [1,5]
We screened the biocatalytic functions of these P450s using 47 small molecules that contain flavonoids, sesquiterpenes, lowmolecular-weight drugs, naphthalene derivatives, and other chemicals with benzene rings [Additional file 1: Figure S3)]
Summary
Cyanobacteria possess several cytochrome P450s, but very little is known about their catalytic functions. CYP110 genes unique to cyanaobacteria are widely distributed in heterocyst-forming cyanobacteria including nitrogen-fixing genera Nostoc and Anabaena. Cyanobacteria possess several cytochrome P450s (P450s), but only a few reports exist regarding their catalytic functions [1,2,3]. P450 CYP110 is a prominent family found in heterocyst-forming cyanobacteria including nitrogenfixing genera Nostoc and Anabaena. CYP110 genes are widely distributed in such cyanobacterial strains [1], e.g., Nostoc ( referred to as Anabaena) sp. CYP110A1 is the first reported cyanobacterial P450 gene, which was present in a conserved 11.25-kb episomal element (the nifD element), and the encoded protein (CYP110A1) was hypothesized to be a fatty acid ω-hydroxylase, based on its substrate binding profile and amino acid sequence similarities to P450BM3 (CYP102A1) of Bacillus megaterium and the mammalian P450 family 4 fatty acid ω-hydroxylase [1,5]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
