Acyl-homoserine lactones (AHLs) are produced by a number of bacterial species and are used by them to regulate the expression of virulence genes in a process known as quorum-sensing. Each bacterial cell has a basal level of AHL and, once the population density reaches a critical level, it triggers AHL-signalling which, in turn, initiates the expression of particular virulence genes . N-(3-Oxohexanoyl)-[acyl-carrier protein] and hexanoyl-[acyl-carrier protein] are the best substrates . The fatty-acyl substrate is derived from fatty-acid biosynthesis through acyl-[acyl-carrier protein] rather than from fatty-acid degradation through acyl-CoA . S-Adenosyl-L-methionine cannot be replaced by methionine, S-adenosylhomocysteine, homoserine or homoserine lactone .
Acyl-homoserine lactones (AHLs) are produced by a number of bacterial species and are used by them to regulate the expression of virulence genes in a process known as quorum-sensing. Each bacterial cell has a basal level of AHL and, once the population density reaches a critical level, it triggers AHL-signalling which, in turn, initiates the expression of particular virulence genes [5]. N-(3-Oxohexanoyl)-[acyl-carrier protein] and hexanoyl-[acyl-carrier protein] are the best substrates [1]. The fatty-acyl substrate is derived from fatty-acid biosynthesis through acyl-[acyl-carrier protein] rather than from fatty-acid degradation through acyl-CoA [1]. S-Adenosyl-L-methionine cannot be replaced by methionine, S-adenosylhomocysteine, homoserine or homoserine lactone [1].
substrate of RhlI, synthesis of a quorum-sensing molecule involved in the regulation of many processes involving the bacterial virulence and infectivity
LasI and LasR form a quorum-sensing system playing a pivotal role in virulence gene regulation of the opportunistic human pathogen Pseudomonas aeruginosa
the enzyme is involved in quorum-sensing signaling by synthesizing the signaling molecules which regulates the virulence genes, N-acylhomoserine lactones are autoinducers, the enzyme acts as a quorum-sensing signal generator, mechanism, overview
the enzyme is involved in quorum-sensing signaling by synthesizing the signaling molecules, the autoinducers N-acylhomoserine lactones, the enzyme acts as a quorum-sensing signal generator
substrate specificity of RhlI, no activity with butyrate, hexanoyl-CoA, and decanoyl-[acyl-carrier-protein], no activity with S-adenosyl-L-homocysteine, S-adenosyl-L-cysteine, L-homoserine lactone, L-homocystein, L-homoserine, and L-methionine as substrates
substrate of RhlI, synthesis of a quorum-sensing molecule involved in the regulation of many processes involving the bacterial virulence and infectivity
LasI and LasR form a quorum-sensing system playing a pivotal role in virulence gene regulation of the opportunistic human pathogen Pseudomonas aeruginosa
the enzyme is involved in quorum-sensing signaling by synthesizing the signaling molecules which regulates the virulence genes, N-acylhomoserine lactones are autoinducers, the enzyme acts as a quorum-sensing signal generator, mechanism, overview
the enzyme is involved in quorum-sensing signaling by synthesizing the signaling molecules, the autoinducers N-acylhomoserine lactones, the enzyme acts as a quorum-sensing signal generator
efficiently inhibits N-acylhomoserine lactone production by isoform RhlI, specifically target short-chain N-acylhomoserine lactone synthase RhlI. trans-Cinnamaldehyde reduces the quorum-sensing-regulated pyocyanin production up to 42%; molecular docking ananlysis, mainly interacts with substrate binding sites. trans-Cinnamaldehyde is locked deeply into the binding site and forms hydrophobic and Pi-Pi interactions with surrounding residues Phe27, Trp33 and Phe105 and one hydrogen bond with Arg30
the LasR protein of Pseudomonas aeruginosa is a central component of a regulatory web that controls the expression of hundreds of genes, some of which play direct roles in disease, molecular mechanism of action of LasR as transcription factor, it detects 3-oxododecanoyl-L-homoserine lactone, overview. The so-called orphan receptor QscR, which also detects 3-oxododecanoyl-L-homoserine lactone. The second quorum sensing receptor, RhlR, detects butanoyl-L-homoserine lactone and interacts with its cognate AHL synthase, RhlI. Unlike LuxR, LasR does not detectably release its N-acyl-homoserine lactone. It binds to six LasR-dependent promoters
quorum sensing regulates motility and lipase, and antifungal activities; quorum sensing regulates motility and lipase, protease, and antifungal activities
quorum sensing systems rely on a signal receptor and a synthase producing N-acyl-homoserine lactone(s) as the signal molecule(s). The rsaL gene, located between the signal receptor and synthase genes, encodes a repressor limiting signal synthase expression and hence signal molecule production, molecular mechannism, overview
chemical communication within populations of bacteria enable them to estimate their population density, a process sometimes referred to as quorum sensing. Signalling among Proteobacteria often involves N-acyl-homoserine lactones, which have identical polar head groups and a variety of hydrophobic acyl groups that differ in length, oxidation, and desaturation. AHL signal molecules are often referred to as autoinducers. They are synthesized by LuxI-type AHL synthases. Most LuxR-type receptors, i.e. LuxR, LasR, and TraR, require N-acyl-homoserine lactones for function and in at least some cases, N-acyl-homoserine lactones are required for protein folding and protease resistance. The LasR/LasI system stimulates production of the RhlI/RhlR system, causing the two Pseudomonas aeruginosa quorum-sensing circuits to initiate sequentially
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
CRYSTALLIZATION (Commentary)
ORGANISM
UNIPROT
LITERATURE
purified recombinant detagged LasIDELTAG, hanging drop vapour diffusion method, from 1.5 M ammonium sulfate, 0.125 M disodium sulfate, and 0.1 M MOPS, pH 6.5, cryoprotection with 15% glycerol, heavy atom derivatization with Hg2+, single isomorphous replacement with anomalous scattering, X-ray diffraction structure determination and analysis at 2.3-3.1 A resolution, structure modeling
strain R2: cells produce twicefold amount of butanoyl homoserine lactone compared to wild type and yield a hexanoyl homoserine lactone level comparable to the butanoyl homoserine lactone concentration
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
PURIFICATION (Commentary)
ORGANISM
UNIPROT
LITERATURE
recombinant His-tagged LasIDELTAG from Escherichia coli by nickel affinity chromatography and gel filtration, the His-tag is removed by thrombin cleavage
RsaLWCS does not show a repressive effect on the promoter of the QS signal synthase gene lasI in Pseudomonas aeruginosa. RsaLWCS formed stable complexes with the promoter of lasI, the gene orthologous to ppuI. RsaLWCS regulates siderophore-mediated growth limitation of plant pathogens and biofilm formation, two processes relevant for plant growth-promoting activity. RsaL binds close to LasR on the same bidirectional promoter, repressing the transcription of both the lasI and rsaL genes. Molecular mechanism, overview
a significant positive correlation is observed between isoform LasI expression and polycyclic aromatic hydrocarbon degradation. Expression of isoform LasI increases with increase in biofilm growth, while the expression of isoform RhlI decreases during log phase of biofilm growth. Degradation of phenanthrene and pyrene by Pseudomonas aeruginosa N6P6 is affected by biofilm growth and LasI expression. The respective phenanthrene degradation for 15, 24, 48, and 72 h old biofilm after 7 days is 21.5, 54.2, 85.6, and 85.7%. The corresponding pyrene degradation is 15, 18.28, 47.56, and 46.48%, respectively, after 7 days
Involvement of quorum sensing genes in biofilm development and degradation of polycyclic aromatic hydrocarbons by a marine bacterium Pseudomonas aeruginosa N6P6