Hopanoid lipids in Bradyrhizobium and other plant-associated bacteria and cloning of the Bradyrhizobium japonicum squalene-hopene cyclase gene

Kannenberg, Elmar L.; Perzl, Michael; M�ller, P.; H�rtner, T.; Poralla, Karl

doi:10.1007/bf00035063

Cited by 16 publications

(6 citation statements)

References 18 publications

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“…SHC has been purified and characterised from Alicyclobacillus acidocaldarius (Bacillus acidocaldarius) 1358 and Rhodopseudomonas palutsris. 1359 The SHC gene has been cloned from Zymomonas mobilis, 1360 Bradyrhizobium japonicum 1361 and A. acidocaldarius 1362 and expressed in Escherichia coli in each case.…”

Section: Biosynthesis Of Hopanoid Triterpenes From Isopentenyl Pyroph...mentioning

confidence: 99%

The biosynthesis of steroids and triterpenoids

Brown¹

1998

Nat. Prod. Rep.

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Section: Biosynthesis Of Hopanoid Triterpenes From Isopentenyl Pyroph...mentioning

confidence: 99%

The biosynthesis of steroids and triterpenoids

Brown¹

1998

Nat. Prod. Rep.

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“…Hopanoids occur in a wide range of Gram-negative and Gram-positive bacteria, including those that form symbiotic associations with plants (3,4); yet, large gaps still exist in our understanding of the breadth of the physiological functions of hopanoids. The localization of hopanoids in membranes has been documented in a variety of different bacteria (5)(6)(7)(8).…”

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confidence: 99%

Lack of Methylated Hopanoids Renders the Cyanobacterium Nostoc punctiforme Sensitive to Osmotic and pH Stress

Garby

Matys

Ongley

et al. 2017

Appl Environ Microbiol

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To investigate the function of 2-methylhopanoids in modern cyanobacteria, the gene coding for the radical-adenosyl methionine (SAM) methylase protein that acts on the C-2 position of hopanoids was deleted from the filamentous cyanobacterium ATCC 29133S. The resulting Δ mutant lacked all 2-methylhopanoids but was found to produce much higher levels of two bacteriohopanepentol isomers than the wild type. Growth rates of the Δ mutant cultures were not significantly different from those of the wild type under standard growth conditions. Akinete formation was also not impeded by the absence of 2-methylhopanoids. The relative abundances of the different hopanoid structures in akinete-dominated cultures of the wild-type and Δ mutant strains were similar to those of vegetative cell-dominated cultures. However, the Δ mutant was found to have decreased growth rates under both pH and osmotic stress, confirming a role for 2-methylhopanoids in stress tolerance. Evidence of elevated photosystem II yield and NAD(P)H-dependent oxidoreductase activity in the Δ mutant under stress conditions, compared to the wild type, suggested that the absence of 2-methylhopanoids increases cellular metabolic rates under stress conditions. As the first group of organisms to develop oxygenic photosynthesis, are central to the evolutionary history of life on Earth and the subsequent oxygenation of the atmosphere. To investigate the origin of cyanobacteria and the emergence of oxygenic photosynthesis, geobiologists use biomarkers, the remnants of lipids produced by different organisms that are found in geologic sediments. 2-Methylhopanes have been considered indicative of cyanobacteria in some environmental settings, with the parent lipids 2-methylhopanoids being present in many contemporary cyanobacteria. We have created a Δ mutant strain that does not produce 2-methylhopanoids to assess the influence of 2-methylhopanoids on stress tolerance. Increased metabolic activity in the mutant under stress indicates compensatory alterations in metabolism in the absence of 2-methylhopanoids.

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“…This is also the case for Rhizobium NGR234, where a cluster of open reading frames (ORFs) with significant similarity to hopanoid biosynthetic genes in Zymomonas mobilis and Bradyrhizobium japonicum [3], including the gene for squalene–hopene cyclase, are encoded by the symbiosis plasmid [4]. Yet, no hopanoids have been detected in laboratory cultures [5], indicating that hopanoids are formed under specific environmental or developmental conditions.…”

Section: Introductionmentioning

confidence: 98%

Hopanoids are formed during transition from substrate to aerial hyphae inStreptomyces coelicolorA3(2)

Poralla

Muth

Härtner

2000

FEMS Microbiology Letters

141

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Streptomyces coelicolor A3(2) contains a cluster of putative isoprenoid and hopanoid biosynthetic genes. The strain does not produce the pentacyclic hopanoids in liquid culture but produces them on solid medium when sporulating. Mutants defective in the formation of aerial mycelium and spores (bld), with the exception of bldB, do not synthesize hopanoids, whereas mutants, which form aerial mycelium but no spores (whi), do. The membrane condensing hopanoids possibly may alleviate stress in aerial mycelium by diminishing water permeability across the membrane.

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Hopanoid lipids in Bradyrhizobium and other plant-associated bacteria and cloning of the Bradyrhizobium japonicum squalene-hopene cyclase gene

Cited by 16 publications

References 18 publications

The biosynthesis of steroids and triterpenoids

The biosynthesis of steroids and triterpenoids

Lack of Methylated Hopanoids Renders the Cyanobacterium Nostoc punctiforme Sensitive to Osmotic and pH Stress

Hopanoids are formed during transition from substrate to aerial hyphae inStreptomyces coelicolorA3(2)

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