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Evolution of substrate recognition sites (SRSs) in cytochromes P450 from Apiaceae exemplified by the CYP71AJ subfamily.

Dueholm B, Krieger C, Drew D, Olry A, Kamo T, Taboureau O, Weitzel C, Bourgaud F, Hehn A, Simonsen HT - BMC Evol. Biol. (2015)

Bottom Line: Large proliferations of cytochrome P450 encoding genes resulting from gene duplications can be termed as 'blooms', providing genetic material for the genesis and evolution of biosynthetic pathways.Homology models underline a significant modification of the accession to the iron atom, which might explain the difference of the substrate specificity between the cytochromes P450 restricted to furanocoumarins as substrates and the orphan CYP71AJ.The subclades show significant variability within their substrate recognition sites between the clades, suggesting different biochemical functions and providing insights into the evolution of cytochrome P450 'blooms' in response to environmental pressures.

View Article: PubMed Central - PubMed

Affiliation: University of Copenhagen, Department of Plant and Environmental Science, Copenhagen Plant Science Centre, Thorvaldsensvej 40, 1871, Frederiksberg C, Denmark. bjorn.dueholm@mymail.unisa.edu.au.

ABSTRACT

Background: Large proliferations of cytochrome P450 encoding genes resulting from gene duplications can be termed as 'blooms', providing genetic material for the genesis and evolution of biosynthetic pathways. Furanocoumarins are allelochemicals produced by many of the species in Apiaceaous plants belonging to the Apioideae subfamily of Apiaceae and have been described as being involved in the defence reaction against phytophageous insects.

Results: A bloom in the cytochromes P450 CYP71AJ subfamily has been identified, showing at least 2 clades and 6 subclades within the CYP71AJ subfamily. Two of the subclades were functionally assigned to the biosynthesis of furanocoumarins. Six substrate recognition sites (SRS1-6) important for the enzymatic conversion were investigated in the described cytochromes P450 and display significant variability within the CYP71AJ subfamily. Homology models underline a significant modification of the accession to the iron atom, which might explain the difference of the substrate specificity between the cytochromes P450 restricted to furanocoumarins as substrates and the orphan CYP71AJ.

Conclusion: Two subclades functionally assigned to the biosynthesis of furanocoumarins and four other subclades were identified and shown to be part of two distinct clades within the CYP71AJ subfamily. The subclades show significant variability within their substrate recognition sites between the clades, suggesting different biochemical functions and providing insights into the evolution of cytochrome P450 'blooms' in response to environmental pressures.

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Cladogram showing the occurrence of the CYP71AJ groups across Apiaceae (tribe names are based on Downie [6, 7]). Grey-colored lineages represent the Apioideae subfamily and * denotes tribes within the apioid superclade. Red triangle: likely origin for angelicin synthase; blue triangles: potential origins for psoralen synthase. A single partial CYP71AJ has been identified in Oenantha javaniva (Oenantheae)
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Fig5: Cladogram showing the occurrence of the CYP71AJ groups across Apiaceae (tribe names are based on Downie [6, 7]). Grey-colored lineages represent the Apioideae subfamily and * denotes tribes within the apioid superclade. Red triangle: likely origin for angelicin synthase; blue triangles: potential origins for psoralen synthase. A single partial CYP71AJ has been identified in Oenantha javaniva (Oenantheae)

Mentions: Recently, Karamat and collaborators [35] identified a single prenyltransferase from parsley able to transform umbelliferone into both demethylsuberosin and osthenol, two dehydrofuranocoumarins that are the precursors of all linear and angular furanocoumarins, respectively. Surprisingly, the same authors showed that both dehydrofuranocoumarin forms are present in plants such as parsley and Ruta graveolens, which do not biosynthesize angular furanocoumarins. Therefore, it seems clear that the limiting step leading to the synthesis of both kinds of isomers is related to the presence of subsequent different cytochromes P450. The biosynthesis of angular furanocoumarins is considered as a more recently evolved trait. The finding of angelicin synthases in the apioid superclade only and with the finding of putative psoralen synthases in earlier diverged lineages support this view. The angelicin synthases have likely occurred from a gene duplication of the psoralen synthase. Given that, the sequence identity between the Angelica (in tribe Selinae) to the Heracleum and Pastinaca (both in tribe Tordyliinae) this is likely to have happened only once (Fig. 5). The ability might have been lost in other Angelica spp., but this is still unresolved.Fig. 5


Evolution of substrate recognition sites (SRSs) in cytochromes P450 from Apiaceae exemplified by the CYP71AJ subfamily.

Dueholm B, Krieger C, Drew D, Olry A, Kamo T, Taboureau O, Weitzel C, Bourgaud F, Hehn A, Simonsen HT - BMC Evol. Biol. (2015)

Cladogram showing the occurrence of the CYP71AJ groups across Apiaceae (tribe names are based on Downie [6, 7]). Grey-colored lineages represent the Apioideae subfamily and * denotes tribes within the apioid superclade. Red triangle: likely origin for angelicin synthase; blue triangles: potential origins for psoralen synthase. A single partial CYP71AJ has been identified in Oenantha javaniva (Oenantheae)
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4482195&req=5

Fig5: Cladogram showing the occurrence of the CYP71AJ groups across Apiaceae (tribe names are based on Downie [6, 7]). Grey-colored lineages represent the Apioideae subfamily and * denotes tribes within the apioid superclade. Red triangle: likely origin for angelicin synthase; blue triangles: potential origins for psoralen synthase. A single partial CYP71AJ has been identified in Oenantha javaniva (Oenantheae)
Mentions: Recently, Karamat and collaborators [35] identified a single prenyltransferase from parsley able to transform umbelliferone into both demethylsuberosin and osthenol, two dehydrofuranocoumarins that are the precursors of all linear and angular furanocoumarins, respectively. Surprisingly, the same authors showed that both dehydrofuranocoumarin forms are present in plants such as parsley and Ruta graveolens, which do not biosynthesize angular furanocoumarins. Therefore, it seems clear that the limiting step leading to the synthesis of both kinds of isomers is related to the presence of subsequent different cytochromes P450. The biosynthesis of angular furanocoumarins is considered as a more recently evolved trait. The finding of angelicin synthases in the apioid superclade only and with the finding of putative psoralen synthases in earlier diverged lineages support this view. The angelicin synthases have likely occurred from a gene duplication of the psoralen synthase. Given that, the sequence identity between the Angelica (in tribe Selinae) to the Heracleum and Pastinaca (both in tribe Tordyliinae) this is likely to have happened only once (Fig. 5). The ability might have been lost in other Angelica spp., but this is still unresolved.Fig. 5

Bottom Line: Large proliferations of cytochrome P450 encoding genes resulting from gene duplications can be termed as 'blooms', providing genetic material for the genesis and evolution of biosynthetic pathways.Homology models underline a significant modification of the accession to the iron atom, which might explain the difference of the substrate specificity between the cytochromes P450 restricted to furanocoumarins as substrates and the orphan CYP71AJ.The subclades show significant variability within their substrate recognition sites between the clades, suggesting different biochemical functions and providing insights into the evolution of cytochrome P450 'blooms' in response to environmental pressures.

View Article: PubMed Central - PubMed

Affiliation: University of Copenhagen, Department of Plant and Environmental Science, Copenhagen Plant Science Centre, Thorvaldsensvej 40, 1871, Frederiksberg C, Denmark. bjorn.dueholm@mymail.unisa.edu.au.

ABSTRACT

Background: Large proliferations of cytochrome P450 encoding genes resulting from gene duplications can be termed as 'blooms', providing genetic material for the genesis and evolution of biosynthetic pathways. Furanocoumarins are allelochemicals produced by many of the species in Apiaceaous plants belonging to the Apioideae subfamily of Apiaceae and have been described as being involved in the defence reaction against phytophageous insects.

Results: A bloom in the cytochromes P450 CYP71AJ subfamily has been identified, showing at least 2 clades and 6 subclades within the CYP71AJ subfamily. Two of the subclades were functionally assigned to the biosynthesis of furanocoumarins. Six substrate recognition sites (SRS1-6) important for the enzymatic conversion were investigated in the described cytochromes P450 and display significant variability within the CYP71AJ subfamily. Homology models underline a significant modification of the accession to the iron atom, which might explain the difference of the substrate specificity between the cytochromes P450 restricted to furanocoumarins as substrates and the orphan CYP71AJ.

Conclusion: Two subclades functionally assigned to the biosynthesis of furanocoumarins and four other subclades were identified and shown to be part of two distinct clades within the CYP71AJ subfamily. The subclades show significant variability within their substrate recognition sites between the clades, suggesting different biochemical functions and providing insights into the evolution of cytochrome P450 'blooms' in response to environmental pressures.

Show MeSH
Related in: MedlinePlus