Steroid biosynthesis in prokaryotes: identification of myxobacterial steroids and cloning of the first bacterial 2,3(S)‐oxidosqualene cyclase from the myxobacterium Stigmatella aurantiaca

  title={Steroid biosynthesis in prokaryotes: identification of myxobacterial steroids and cloning of the first bacterial 2,3(S)‐oxidosqualene cyclase from the myxobacterium Stigmatella aurantiaca},
  author={Helge B. Bode and Bernd Zeggel and Barbara Silakowski and Silke C Wenzel and Hans Prof Dr Reichenbach and Rolf M{\"u}ller},
  journal={Molecular Microbiology},
Steroids, such as cholesterol, are synthesized in almost all eukaryotic cells, which use these triterpenoid lipids to control the fluidity and flexibility of their cell membranes. Bacteria rarely synthesize such tetracyclic compounds but frequently replace them with a different class of triterpenoids, the pentacyclic hopanoids. The intriguing mechanisms involved in triterpene biosynthesis have attracted much attention, resulting in extensive studies of squalene‐hopene cyclase in bacteria and (S… 
Sterol Biosynthesis by a Prokaryote: First in Vitro Identification of the Genes Encoding Squalene Epoxidase and Lanosterol Synthase from Methylococcus capsulatus
This is the first report demonstrating the existence of the genes encoding squalene epoxidase and lanosterol synthase in prokaryotes by establishing the enzyme activities.
Biosynthesis of steroidal antibiotic fusidanes: functional analysis of oxidosqualene cyclase and subsequent tailoring enzymes from Aspergillus fumigatus.
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Essentiality of sterol synthesis genes in the planctomycete bacterium Gemmata obscuriglobus
It is shown that sterols are essential for growth of G. obscuriglobus, and that sterol depletion leads to aberrant membrane structures and defects in budding cell division, which advances the understanding of sterol distribution and function.
Lanosterol biosynthesis in the prokaryote Methylococcus capsulatus: insight into the evolution of sterol biosynthesis.
A putative operon containing homologues of essential eukaryotic sterol biosynthetic enzymes, squalene monooxygenase and oxidosqualene cyclase, has been identified in the genome of the prokaryote
Phylogenetic and biochemical evidence for sterol synthesis in the bacterium Gemmata obscuriglobus
The primitive sterols produced by Gemmata suggest that this genus could retain the most ancient remnants of the sterol biosynthetic pathway, which was exchanged between bacteria and early eukaryotes via lateral gene transfer or endosymbiotic events.
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Investigation of the biosynthesis with labelled precursors revealed acetate, butyrate and phenylalanine as building blocks for 1.
Biosynthesis of Structurally Diverse Triterpenes in Plants: the Role of Oxidosqualene Cyclases
The role of OSCs in generating triterpene skeletal diversity in plants is highlighted, and some triterpenes are suggested to play specialized/secondary function as defence compounds.
Divergent evolution of oxidosqualene cyclases in plants.
The phylogenetic analysis suggests that expansion of OSC members in higher plants has occurred mainly through tandem duplication followed by positive selection and diversifying evolution, and consolidated the previous suggestion that dicot triterpene synthases have been derived from an ancestral lanosterol synthase instead of directly from their cycloartenol synthases.


The Biosynthesis of the Aromatic Myxobacterial Electron Transport Inhibitor Stigmatellin Is Directed by a Novel Type of Modular Polyketide Synthase*
Results of feeding experiments are in good agreement with the proposed biosynthetic scheme, and in contrast to all other PKS type I systems reported to date, each module of StiA–J is encoded on a separate gene.
Squalene-hopene cyclase from Methylococcus capsulatus (Bath): a bacterium producing hopanoids and steroids.
Non-specific lanosterol and hopanoid biosynthesis be a cell-free system from the bacterium Methylococcus capsulatus.
The presence of a squalene epoxide/lanosterol cyclase activity, which was suspected in view of the unique 3 beta-hydroxy 4 alpha-methyl steroids of M. capsulatus, was demonstrated by the labelling of lanosterol, and it was shown that this does not derive from Lanosterol by isomerization via a 3-oxo compound.
Hopanoid Biosynthesis and Function in Bacteria
The many structural variants of hopanoids indicate that they may have other interesting but as yet unknown functions, including membrane components involved in regulating membrane fluidity and stability.
Non-specific biosynthesis of hopane triterpenes by a cell-free system from Acetobacter pasteurianum.
This bacterial homogenate is capable of cyclizing an unnatural substrate, 2,3-epoxy-squalene, into 3-hydroxyhopanoids normally absent in the bacterium, and accepts the replacement of the normal substrate, squalene, by the corresponding epoxide.
Isoprenoid biosynthesis in bacteria: two different pathways?
Results indicate that at least two different pathways for the biosynthesis of isopentenylpyrophosphate are present in bacteria, and demonstrate the in vitro operation of acetoacetate pathway for the formation of isOPentenypyroph phosphate in bacteria.
The myxochelin iron transport regulon of the myxobacterium Stigmatella aurantiaca Sg a15.
The biosynthetic gene cluster of the myxochelin-type iron chelator was cloned from Stigmatella aurantiaca Sg a15 and characterized. This catecholate siderophore was only known from two other
A Novel Biosynthetic Pathway Providing Precursors for Fatty Acid Biosynthesis and Secondary Metabolite Formation in Myxobacteria*
During studies on myxothiazol biosynthesis in the myxobacterium, Stigmatella aurantiaca, a novel biosynthetic route to isovaleric acid was detected, providing evidence for a novel branch of the mevalonate pathway involving the intermediate 3,3-dimethylacryloyl-CoA.