scholarly journals noeM, a New Nodulation Gene Involved in the Biosynthesis of Nod Factors with an Open-Chain Oxidized Terminal Residue and in the Symbiosis with Mimosa pudica

2019 ◽  
Vol 32 (12) ◽  
pp. 1635-1648 ◽  
Author(s):  
Benoit Daubech ◽  
Verena Poinsot ◽  
Agnieszka Klonowska ◽  
Delphine Capela ◽  
Clémence Chaintreuil ◽  
...  
Keyword(s):  
Transmembrane Protein ◽  
Fatty Acyl ◽  
Mimosa Pudica ◽  
Nod Factors ◽  
Open Chain ◽  
Nod Factor ◽  
Terminal Residue ◽  
Fatty Acid Hydroxylase ◽  
Acyl Chains

The β-rhizobium Cupriavidus taiwanensis is a nitrogen-fixing symbiont of Mimosa pudica. Nod factors produced by this species were previously found to be pentameric chitin-oligomers carrying common C18:1 or C16:0 fatty acyl chains, N-methylated and C-6 carbamoylated on the nonreducing terminal N-acetylglucosamine and sulfated on the reducing terminal residue. Here, we report that, in addition, C. taiwanensis LMG19424 produces molecules where the reducing sugar is open and oxidized. We identified a novel nodulation gene located on the symbiotic plasmid pRalta, called noeM, which is involved in this atypical Nod factor structure. noeM encodes a transmembrane protein bearing a fatty acid hydroxylase domain. This gene is expressed during symbiosis with M. pudica and requires NodD and luteolin for optimal expression. The closest noeM homologs formed a separate phylogenetic clade containing rhizobial genes only, which are located on symbiosis plasmids downstream from a nod box. Corresponding proteins, referred to as NoeM, may have specialized in symbiosis via the connection to the nodulation pathway and the spread in rhizobia. noeM was mostly found in isolates of the Mimoseae tribe, and specifically detected in all tested strains able to nodulate M. pudica. A noeM deletion mutant of C. taiwanensis was affected for the nodulation of M. pudica, confirming the role of noeM in the symbiosis with this legume.

How do mechanosensitive channels sense membrane tension?

2016 ◽  
Vol 44 (4) ◽  
pp. 1019-1025 ◽  
Author(s):  
Tim Rasmussen
Keyword(s):  
Membrane Lipids ◽  
Osmotic Shock ◽  
Md Simulations ◽  
Fatty Acyl ◽  
Membrane Bilayer ◽  
Cross Sectional ◽  
Conducting Path ◽  
Lipid Chain ◽  
Acyl Chains

Mechanosensitive (MS) channels provide protection against hypo-osmotic shock in bacteria whereas eukaryotic MS channels fulfil a multitude of important functions beside osmoregulation. Interactions with the membrane lipids are responsible for the sensing of mechanical force for most known MS channels. It emerged recently that not only prokaryotic, but also eukaryotic, MS channels are able to directly sense the tension in the membrane bilayer without any additional cofactor. If the membrane is solely viewed as a continuous medium with specific anisotropic physical properties, the sensitivity towards tension changes can be explained as result of the hydrophobic coupling between membrane and transmembrane (TM) regions of the channel. The increased cross-sectional area of the MS channel in the active conformation and elastic deformations of the membrane close to the channel have been described as important factors. However, recent studies suggest that molecular interactions of lipids with the channels could play an important role in mechanosensation. Pockets in between TM helices were identified in the MS channel of small conductance (MscS) and YnaI that are filled with lipids. Less lipids are present in the open state of MscS than the closed according to MD simulations. Thus it was suggested that exclusion of lipid fatty acyl chains from these pockets, as a consequence of increased tension, would trigger gating. Similarly, in the eukaryotic MS channel TRAAK it was found that a lipid chain blocks the conducting path in the closed state. The role of these specific lipid interactions in mechanosensation are highlighted in this review.

scholarly journals Rhizobium sp. BR816 Produces a Complex Mixture of Known and Novel Lipochitooligosaccharide Molecules

2001 ◽  
Vol 14 (5) ◽  
pp. 678-684 ◽  
Author(s):  
Carla Snoeck ◽  
Ellen Luyten ◽  
Véréna Poinsot ◽  
Arlette Savagnac ◽  
Jos Vanderleyden ◽  
...  
Keyword(s):  
Complex Mixture ◽  
Fatty Acyl ◽  
Nodule Development ◽  
Signal Molecules ◽  
Plant Responses ◽  
Broad Host Range ◽  
Terminal Residue ◽  
Acetyl Group ◽  
Acyl Chains ◽  
Rhizobium Sp

Rhizobial lipochitooligosaccharide (LCO) signal molecules induce various plant responses, leading to nodule development. We report here the LCO structures of the broad-host range strain Rhizobium sp. BR816. The LCOs produced are all pentamers, carrying common C18:1 or C18:0 fatty acyl chains, N-methylated and C-6 carbamoylated on the nonreducing terminal N-acetylglucosamine and sulfated on the reducing/terminal residue. A second acetyl group can be present on the penultimate N-acetylglu-cosamine from the nonreducing terminus. Two novel characteristics were observed: the reducing/terminal residue can be a glucosaminitol (open structure) and the degree of acetylation of this glucosaminitol or of the reducing residue can vary.

scholarly journals Widespread Head-to-Head Hydrocarbon Biosynthesis in Bacteria and Role of OleA

2010 ◽  
Vol 76 (12) ◽  
pp. 3850-3862 ◽  
Author(s):  
David J. Sukovich ◽  
Jennifer L. Seffernick ◽  
Jack E. Richman ◽  
Jeffrey A. Gralnick ◽  
Lawrence P. Wackett
Keyword(s):  
Xanthomonas Campestris ◽  
Gene Deletion ◽  
Shewanella Oneidensis ◽  
Fatty Acyl ◽  
Double Bonds ◽  
Acyl Chains ◽  
Hydrocarbon Biosynthesis ◽  
Structural Alignments ◽  
Long Chain

ABSTRACT Previous studies identified the oleABCD genes involved in head-to-head olefinic hydrocarbon biosynthesis. The present study more fully defined the OleABCD protein families within the thiolase, α/β-hydrolase, AMP-dependent ligase/synthase, and short-chain dehydrogenase superfamilies, respectively. Only 0.1 to 1% of each superfamily represents likely Ole proteins. Sequence analysis based on structural alignments and gene context was used to identify highly likely ole genes. Selected microorganisms from the phyla Verucomicrobia, Planctomyces, Chloroflexi, Proteobacteria, and Actinobacteria were tested experimentally and shown to produce long-chain olefinic hydrocarbons. However, different species from the same genera sometimes lack the ole genes and fail to produce olefinic hydrocarbons. Overall, only 1.9% of 3,558 genomes analyzed showed clear evidence for containing ole genes. The type of olefins produced by different bacteria differed greatly with respect to the number of carbon-carbon double bonds. The greatest number of organisms surveyed biosynthesized a single long-chain olefin, 3,6,9,12,15,19,22,25,28-hentriacontanonaene, that contains nine double bonds. Xanthomonas campestris produced the greatest number of distinct olefin products, 15 compounds ranging in length from C28 to C31 and containing one to three double bonds. The type of long-chain product formed was shown to be dependent on the oleA gene in experiments with Shewanella oneidensis MR-1 ole gene deletion mutants containing native or heterologous oleA genes expressed in trans. A strain deleted in oleABCD and containing oleA in trans produced only ketones. Based on these observations, it was proposed that OleA catalyzes a nondecarboxylative thiolytic condensation of fatty acyl chains to generate a β-ketoacyl intermediate that can decarboxylate spontaneously to generate ketones.

scholarly journals Accessory proteins of the zDHHC family of S-acylation enzymes

2020 ◽  
Vol 133 (22) ◽  
pp. jcs251819
Author(s):  
Christine Salaun ◽  
Carolina Locatelli ◽  
Filip Zmuda ◽  
Juan Cabrera González ◽  
Luke H. Chamberlain
Keyword(s):  
Fatty Acyl ◽  
Accessory Proteins ◽  
Enzyme Substrate ◽  
Essential Components ◽  
Selenoprotein K ◽  
Acyl Chains ◽  
The Stability ◽  
And Function ◽  
Encoding Genes

ABSTRACTAlmost two decades have passed since seminal work in Saccharomyces cerevisiae identified zinc finger DHHC domain-containing (zDHHC) enzymes as S-acyltransferases. These enzymes are ubiquitous in the eukarya domain, with 23 distinct zDHHC-encoding genes in the human genome. zDHHC enzymes mediate the bulk of S-acylation (also known as palmitoylation) reactions in cells, transferring acyl chains to cysteine thiolates, and in so-doing affecting the stability, localisation and function of several thousand proteins. Studies using purified components have shown that the minimal requirements for S-acylation are an appropriate zDHHC enzyme–substrate pair and fatty acyl-CoA. However, additional proteins including GCP16 (also known as Golga7), Golga7b, huntingtin and selenoprotein K, have been suggested to regulate the activity, stability and trafficking of certain zDHHC enzymes. In this Review, we discuss the role of these accessory proteins as essential components of the cellular S-acylation system.

scholarly journals The Production of Species-Specific Highly Unsaturated Fatty Acyl-Containing LCOs from Rhizobium leguminosarum bv. trifolii Is Stringently Regulated by nodD and Involves the nodRL Genes

2006 ◽  
Vol 19 (3) ◽  
pp. 215-226 ◽  
Author(s):  
Helmi R. M. Schlaman ◽  
Maurien M. A. Olsthoorn ◽  
Marga Harteveld ◽  
Lucie Dörner ◽  
Michael A. Djordjevic ◽  
...  
Keyword(s):  
Rhizobium Leguminosarum ◽  
Growth Conditions ◽  
Fatty Acyl ◽  
Nod Factors ◽  
Wild Type ◽  
Reading Frame ◽  
Nod Genes ◽  
Geographical Regions ◽  
Acyl Chains ◽  
Species Specific

A proportion of the Nod factors of some Rhizobium leguminosarum bv. trifolii strains is characterized by the presence of highly unsaturated fatty acyl chains containing trans double bonds in conjugation with the carbonyl group of the glycan oligosaccharide backbone. These fatty acyl chains are C18:3, C20:3, C18:4, or C20:4 and have UV-absorption maxima at 303 and 330 nm. These Nod factors are presumed to be important for host-specific nodulation on clover species. However, in wild-type R. leguminosarum bv. trifolii ANU843, Nod factors with these characteristic acyl chains were not observed using standard growth conditions. They were observed only when nod genes were present in multiple copies or when transcription was artificially increased to higher levels by introduction of extra copies of the transcriptional regulator gene nodD. In a screen for the genetic requirements for production of the Nod factors with these characteristic structures, it was found that the region downstream of nodF and nodE is essential for the presence of highly unsaturated fatty acyl moieties. Mu-lacZ insertion in this region produced a mutant that did not produce detectable levels of the highly unsaturated fatty acyl-bearing Nod factors. The Mu-lacZ insertion was translationally fused to a putative new gene, designated nodR, in the nodE-nodL intergenic region; however, no predicted function for the putative NodR protein has been obtained from data-base homology searches. In a set of 12 wild-type strains of R. leguminosarum bv. trifolii originating from various geographical regions that were analyzed for the presence of a nodR-like gene, it was found that seven strains carry a homologous NodR open reading frame. Taken together, our results suggest a tightly controlled regulation of nod genes, in which we propose that it is the balance of transcriptional levels of nodFE and the nodRL genes that is critical for determining the presence of highly unsaturated fatty acyl moieties in the Nod factors produced by R. leguminosarum bv. trifolii.

The effect of methyl lidocaine on lysophospholipid metabolism in hamster heart

1990 ◽  
Vol 68 (4) ◽  
pp. 745-750 ◽  
Author(s):  
Paul G. Tardi ◽  
Ricky Y. K. Man ◽  
Christopher R. McMaster ◽  
Patrick C. Choy
Keyword(s):  
Physiological Role ◽  
Fatty Acyl ◽  
The Other ◽  
Acylation Reaction ◽  
Alternate Pathway ◽  
Mammalian Tissues ◽  
High Concern ◽  
Acyl Chains ◽  
Hamster Heart

An important feature in the remodelling of fatty acyl chains in cellular phospholipids is the acylation of lysophospholipids. Since lysophospholipids are cytolytic al high concern rat ions, the acylation reaction may provide an alternate pathway for the removal of cellular lysophospholipids. However, the physiological role of the acylation process in the maintenance of lysophospholipid levels in mammalian tissues has not been clearly defined. In this study, methyl lidocaine was found to inhibit both lysophosphatidylcholine:acyl-CoA and lysophosphatidylethanolamine:acyl-CoA acyltransferase activities in the hamster heart, but the drug had no effect on the other lysophospholipid metabolic enzymes. When the heart was perfused with 0.5 mg methyl lidocaine/mL, acyltransferase activities were attenuated, but there was no change in the activities of phospholipase A or lysophospholipase. The levels of the major lysophospholipids in the heart were not altered by methyl lidocaine perfusion. When the hearts were perfused with labelled lysophospholipid in the presence of methyl lidocaine, there was a reduction in the formation of the phospholipid and an increase in the release of the free fatty acid. However, the labelling of lysophospholipid in the heart was not altered by methyl lidocaine. We postulate that the acylation reaction has no direct contribution to the maintenance of the lysophospholipid levels in the heart.Key words: lysophosphatidylcholine, lysophosphatidylethanolamine, acyltransferase, methyl lidocaine, hamster heart.

scholarly journals Carbamoylation of Azorhizobial Nod Factors Is Mediated by NodU

1999 ◽  
Vol 12 (1) ◽  
pp. 68-73 ◽  
Author(s):  
Wim D'Haeze ◽  
Marc Van Montagu ◽  
Jean-Claude Promé ◽  
Marcelle Holsters
Keyword(s):  
Escherichia Coli ◽  
Structural Analysis ◽  
Nod Factors ◽  
Azorhizobium Caulinodans ◽  
Terminal Residue ◽  
Azorhizobium Caulinodans Ors571 ◽  
Sequence Similarities ◽  
Carbamoyl Group

Lipochitooligosaccharides (LCOs) synthesized by Azorhizobium caulinodans ORS571 are substituted at the nonreducing-terminal residue with a 6-O-carbamoyl group. LCO biosynthesis in A. caulinodans is dependent on the nodABCSUIJZnoeC operon. Until now, the role of the nodulation protein NodU in the synthesis of azorhizobial LCOs remained unclear. Based on sequence similarities and structural analysis of LCOs produced by a nodU mutant, a complemented nodU mutant, and Escherichia coli DH5α expressing the nodABCSU genes, NodU was shown to be involved in the carbamoylation step.

scholarly journals Nodulation Gene Mutants of Mesorhizobium loti R7A—nodZ and nolL Mutants Have Host-Specific Phenotypes on Lotus spp.

2009 ◽  
Vol 22 (12) ◽  
pp. 1546-1554 ◽  
Author(s):  
Patsarin Rodpothong ◽  
John T. Sullivan ◽  
Kriangsak Songsrirote ◽  
David Sumpton ◽  
Kenneth W. J.-T. Cheung ◽  
...  
Keyword(s):  
Factor Structure ◽  
Infection Thread ◽  
Plant Responses ◽  
Nod Factors ◽  
Nod Factor ◽  
Mesorhizobium Loti ◽  
Terminal Residue ◽  
Nodulation Genes ◽  
Thread Formation ◽  
Infection Thread Formation

Rhizobial Nod factors induce plant responses and facilitate bacterial infection, leading to the development of nitrogen-fixing root nodules on host legumes. Nodule initiation is highly dependent on Nod-factor structure and, hence, on at least some of the nodulation genes that encode Nod-factor production. Here, we report the effects of mutations in Mesorhizobium loti R7A nodulation genes on nodulation of four Lotus spp. and on Nod-factor structure. Most mutants, including a ΔnodSΔnolO double mutant that produced Nod factors lacking the carbamoyl and possibly N-methyl groups on the nonreducing terminal residue, were unaffected for nodulation. R7AΔnodZ and R7AΔnolL mutants that produced Nod factors without the (acetyl)fucose on the reducing terminal residue had a host-specific phenotype, forming mainly uninfected nodule primordia on Lotus filicaulis and L. corniculatus and effective nodules with a delay on L. japonicus. The mutants also showed significantly reduced infection thread formation and Nin gene induction. In planta complementation experiments further suggested that the acetylfucose was important for balanced signaling in response to Nod factor by the L. japonicus NFR1/NFR5 receptors. Overall the results reveal differences in the sensitivity of plant perception with respect to signaling leading to root hair deformation and nodule primordium development versus infection thread formation and rhizobial entry.

scholarly journals Role of lipid reactions in quality of oat products

2008 ◽  
Vol 13 (1-2) ◽  
pp. 88 ◽  
Author(s):  
P. LEHTINEN ◽  
S. LAAKSO
Keyword(s):  
Fatty Acyl ◽  
Enzymatic Oxidation ◽  
Food Markets ◽  
Huge Impact ◽  
Acyl Chains ◽  
Underlying Mechanisms ◽  
Hydrolysis Of ◽  
Global Food

In traditional oat processing practice the control of lipid reactions relies largely on empirical experiences and dogmatic principles rather than on profound understanding of the underlying mechanisms. However, in today’s global food markets, the industry faces strict challenges in the development of new processes and applications where the prior experience is unsatisfactory or insufficient. The storage stability of novel oat products can be greatly enhanced by taking the mechanisms of lipid deterioration into account, and by adjusting the processing conditions accordingly so that these reactions can be minimized. The lipid reactions in oat products result in two different unwanted properties: bitter, astringent, taste or a rancid flavor. Chemically, these properties are associated to enzymatic hydrolysis of ester bonds and non-enzymatic oxidation of unsaturated fatty acyl chains respectively. The processing history oat product has a huge impact on which of these reactions predominates in oat products. The review focuses on the reactions of lipids in processed oat products, and identifies factors that are critical for enhanced shelf-life.;

Alfalfa nodulation by Sinorhizobium fredii does not require sulfated Nod-factors

2003 ◽  
Vol 30 (12) ◽  
pp. 1219 ◽  
Author(s):  
Sadaf Noreen ◽  
Helmi R. M. Schlaman ◽  
Ramón A. Bellogín ◽  
Ana M. Buendía-Clavería ◽  
MaríaRosario Espuny ◽  
...  
Keyword(s):  
Acyl Chain ◽  
Fatty Acyl ◽  
Fatty Acyl Chain ◽  
Insertion Mutation ◽  
Rhizobium Strain ◽  
Nod Factors ◽  
Sinorhizobium Fredii ◽  
Nod Factor ◽  
Nodulation Capacity ◽  
Soybean Nodulation

Rhizobium strain 042B(s) is able to nodulate both soybean and alfalfa cultivars. We have demonstrated, by mass spectrometry, that the nodulation (Nod) factors produced by this strain are characteristic of those produced by Sinorhizobium fredii, which typically nodulates soybean; they have 3–5 N-acetylglucosamine (GlcNAc) residues, a mono-unsaturated or saturated C16, C18 or C20 fatty-acyl chain, and a (methyl)fucosyl residue on C6 of the reducing-terminal GlcNAc. In order to study Rhizobium strain 042B(s) and its nodulation behaviour further, we introduced an insertion mutation in the noeL gene, which is responsible for the presence of the (methyl)fucose residue on the reducing terminal GlcNAc of the Nod-factors, yielding mutant strain SVQ523. A plasmid (pHM500) carrying nodH, nodP and nodQ, the genes involved in sulfation of Nod-factors on C6 of the reducing-terminal GlcNAc, was introduced into SVQ523, generating SVQ523.pHM500. As expected, strain SVQ523 produces unfucosylated Nod-factors, while SVQ523.pHM500 produces both unfucosylated and unfucosylated sulfated Nod-factors. Plant tests showed that soybean nodulation was reduced if the inoculant (SVQ523.pHM500) produced sulfated Nod-factors. In the Asiatic alfalfa cultivar Baoding, SVQ523 (absence of a substitution at C6) failed to nodulate, but both 042B(s) (fucosyl at C6) and SVQ523.pHM500 (sulfate at C6) formed nodules. In contrast, SVQ523 showed enhanced nodulation capacity with the western alfalfa cultivars ORCA and ARC. These results indicate that Nod-factor sulfation is not a requisite for S. fredii to nodulate alfalfa.

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