Labeling Studies Clarify the Committed Step in Bacterial Gibberellin Biosynthesis

Nett, Ryan S.; Dickschat, Jeroen S.; Peters, Reuben J.

doi:10.1021/acs.orglett.6b02569

Cited by 14 publications

(19 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Notably, unlike recombinantly expressed CYP114+Fd GA from other bacteria, including those from X. hydroxykaurenoic acid to a similar mixture of GA 12 -aldehyde and lesser amounts of GA 12 (Supplemental Figure S4B). Consistent with previous work on the CYP114+Fd GA from the α-rhizobia S. fredii (Nett et al, 2016), trace amounts of ent -6α,7α-dihydroxykaurenoic acid was observed here, but neither this (Supplemental Figure S4C+B), nor the closely related kaurenolide or 7β-hydroxykaurenolide (neither of which were observed here) appeared to be further transformed by Et CYP114+ Et Fd GA (data not shown).…”

Section: Resultssupporting

confidence: 92%

“…This enabled demonstration of the specific production of GGDP by the associated IDSs, rather than a mixture of different chain length products as seen with other such enzymes (Schmidt et al, 2010; Nagel et al, 2015), which is consistent with dedicated production of the derived GAs. In addition, the ability of Et CYP114+ Et Fd GA to convert ent -7α-hydroxykaurenoic acid to GA 12 -aldehyde further supports the relevance of this intermediate, consistent with recent labeling experiments (Nett et al, 2016). …”

Section: Discussionsupporting

confidence: 86%

See 1 more Smart Citation

Investigating the Phylogenetic Range of Gibberellin Biosynthesis in Bacteria

Nagel

Peters

2017

MPMI

Self Cite

View full text Add to dashboard Cite

Summary Certain plant-associated microbes can produce gibberellin (GA) phytohormones, as first described for the rice fungal pathogen Gibberella fujikuroi and more recently for bacteria, including several rhizobia and the rice bacterial pathogen Xanthomonas oryzae pv. oryzicola. The relevant enzymes are encoded by a biosynthetic operon that exhibits both a greater phylogenetic range and scattered distribution among plant-associated bacteria. Here the phylogenetic distribution of this operon was investigated. To demonstrate conserved functionality, the enzymes encoded by the disparate operon from Xanthomonas translucens pv. translucens, along with those from the most divergent example, found in Erwinia tracheiphila, were biochemically characterized. In both of these phytopathogens the operon leads to production of the bioactive GA4. Based on these results, it seems that this operon is widely dedicated to GA biosynthesis. However, there is intriguing variation in exact product. In particular, although all plant pathogens seem to produce bioactive GA4, rhizobia generally only produce the penultimate hormonal precursor GA9. This is suggested to reflect their distinct interactions with plants, as production of GA4 counteracts the jasmonic acid-mediated defense response, reflecting the importance of wounds as the entry point for these phytopathogens, while such suppression presumably is detrimental in the rhizobial symbiotic relationship.

show abstract

Section: Resultssupporting

confidence: 92%

Section: Discussionsupporting

confidence: 86%

Investigating the Phylogenetic Range of Gibberellin Biosynthesis in Bacteria

Nagel

Peters

2017

MPMI

Self Cite

View full text Add to dashboard Cite

show abstract

“…Both constructs were expressed in E. coli and ent -kaurenoic acid was added to the resulting cultures. Cultures expressing Pm CYP114 + Pm Fd (i.e., without the SDR) produced a mixture of GA 12 -aldehyde and GA 12 , while the Pm CYP114 + Pm Fd-SDR construct exclusively produced GA 12 , with the putative intermediate ent -7α-hydroxykaurenoic acid not observed in either case (Figure 4 and Supplementary Figure S1 ), consistent with previous mechanistic investigation of this reaction ( Nett et al, 2016 ). This demonstrated the ability of the Fd to enable full CYP114 activity as a fusion protein with the SDR, as well as the expected more efficient oxidation of GA 12 -aldehyde to GA 12 by the SDR.…”

Section: Resultssupporting

confidence: 88%

A Third Class: Functional Gibberellin Biosynthetic Operon in Beta-Proteobacteria

et al. 2018

Self Cite

View full text Add to dashboard Cite

The ability of plant-associated microbes to produce gibberellin A (GA) phytohormones was first described for the fungal rice pathogen Gibberella fujikuroi in the 1930s. Recently the capacity to produce GAs was shown for several bacteria, including symbiotic alpha-proteobacteria (α-rhizobia) and gamma-proteobacteria phytopathogens. All necessary enzymes for GA production are encoded by a conserved operon, which appears to have undergone horizontal transfer between and within these two phylogenetic classes of bacteria. Here the operon was shown to be present and functional in a third class, the beta-proteobacteria, where it is found in several symbionts (β-rhizobia). Conservation of function was examined by biochemical characterization of the enzymes encoded by the operon from Paraburkholderia mimosarum LMG 23256T. Despite the in-frame gene fusion between the short-chain alcohol dehydrogenase/reductase and ferredoxin, the encoded enzymes exhibited the expected activity. Intriguingly, together these can only produce GA9, the immediate precursor to the bioactive GA4, as the cytochrome P450 (CYP115) that catalyzes the final hydroxylation reaction is missing, similar to most α-rhizobia. However, phylogenetic analysis indicates that the operon from β-rhizobia is more closely related to examples from gamma-proteobacteria, which almost invariably have CYP115 and, hence, can produce bioactive GA4. This indicates not only that β-rhizobia acquired the operon by horizontal gene transfer from gamma-proteobacteria, rather than α-rhizobia, but also that they independently lost CYP115 in parallel to the α-rhizobia, further hinting at the possibility of detrimental effects for the production of bioactive GA4 by these symbionts.

show abstract

“…Oxidation with ring contraction to GA 12 aldehyde (41) by CYP114 proceeds with specific extrusion of C-7, as demonstrated by a 13 C-labelling experiment through feeding with (2-13 C)mevalonolactone. [58] This step is followed by an oxidation to GA 12 (42)b yS DR GA .T he final oxidations to GA 15 (43), GA 24 (44), and GA 9 (45)a re performed by CYP112. [57] Notably,t he identified pathway intermediates and reactions are essentially the same as in plants and fungi, but the responsible enzymes are completely unrelated in all three cases,thus giving an interesting example of convergent evolution.…”

Section: Ent-copalyl Diphosphate Synthasementioning

confidence: 99%

Bacterial Diterpene Biosynthesis

Dickschat

2019

Angew Chem Int Ed

Self Cite

113

View full text Add to dashboard Cite

This Minireview summarises recent developments in the biosynthesis of diterpenes by diterpene synthases in bacteria. It is structured by the class of enzyme involved in the first committed step towards diterpenes, starting with type I diterpene synthases, followed by type II enzymes and the more recently discovered UbiA‐related diterpene synthases. A special emphasis lies on the reaction mechanisms of diterpene synthases that convert simple linear precursors through cationic cascades into structurally complex, usually polycyclic carbon skeletons with multiple stereogenic centres. A further main focus of this Minireview is a discussion of how these mechanisms can be unravelled. Downstream modifications to bioactive molecules are also covered.

show abstract

Labeling Studies Clarify the Committed Step in Bacterial Gibberellin Biosynthesis

Cited by 14 publications

References 32 publications

Investigating the Phylogenetic Range of Gibberellin Biosynthesis in Bacteria

Investigating the Phylogenetic Range of Gibberellin Biosynthesis in Bacteria

A Third Class: Functional Gibberellin Biosynthetic Operon in Beta-Proteobacteria

Bacterial Diterpene Biosynthesis

Contact Info

Product

Resources

About