Acyl-homoserine-L-lactones (AHLs) are diffusible chemical signals that are required for virulence of many Gram-negative bacteria. AHLs are produced by AHL synthases from two substrates, S-adenosyl-L-methionine and acyl-acyl carrier protein. The AHL synthase EsaI, which is homologous to the AHL synthases from other pathogenic bacterial species, has been crystallized in the primitive tetragonal space group P4(3), with unit-cell parameters a = b = 66.40, c = 47.33 A. The structure was solved by multiple-wavelength anomalous diffraction with a novel use of the rhenium anomalous signal. The rhenium-containing structure has been refined to a resolution of 2.5 A and the perrhenate ion binding sites and liganding residues have been identified.
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http://dx.doi.org/10.1107/s0907444901014512 | DOI Listing |
Mol Cell
December 2024
Department of Cell Biology, Cancer Institute, Japanese Foundation for Cancer Research, Koto-ku, Tokyo 135-8550, Japan. Electronic address:
Viral mimicry driven by endogenous double-stranded RNA (dsRNA) stimulates innate and adaptive immune responses. However, the mechanisms that regulate dsRNA-forming transcripts during cancer therapy remain unclear. Here, we demonstrate that dsRNA is significantly accumulated in cancer cells following pharmacologic induction of micronuclei, stimulating mitochondrial antiviral signaling (MAVS)-mediated dsRNA sensing in conjunction with the cyclic GMP-AMP synthase (cGAS)/stimulator of interferon genes (STING) pathway.
View Article and Find Full Text PDFBiochem Biophys Res Commun
August 2019
College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China. Electronic address:
Despite the conservative DNA sequences among LuxI (Acyl Homoserine Lactones synthase gene) homologs, structure-product relationship of AHL synthase remains to be elucidated. In this study, through degenerate primers and in vitro expression methods, we collected the information of the gene sequences and AHL profiles from nine LuxIs among Ensifer adhaerens strains. The chromosome-encoded LuxI (C-LuxI) distinguished themselves from the plasmid-encoded ones (P-LuxI) not only in the DNA sequences, but also in AHL profiles.
View Article and Find Full Text PDFFront Bioeng Biotechnol
April 2019
School of Biological and Health Systems Engineering, Arizona State University, Tempe, AZ, United States.
Gene regulators that are controlled by membrane-permeable compounds called homoserine lactones (HSLs) have become popular tools for building synthetic gene networks that coordinate behaviors across populations of engineered bacteria. Synthetic HSL-signaling systems are derived from natural DNA and protein elements from microbial quorum signaling pathways. Crosstalk, where a single HSL can activate multiple regulators, can lead to faults in networks composed of parallel signaling pathways.
View Article and Find Full Text PDFMicrob Pathog
January 2019
Department of Agricultural Microbiology, Aligarh Muslim University, Aligarh, UP, 202002, India. Electronic address:
The emerging prevalence of multidrug-resistance in Gram-negative pathogens, due to conventional antimicrobial therapeutics, has led the researchers to emphasize on development of alternative novel strategies to suppress the bacterial virulence and pathogenicity through inhibition of quorum sensing (QS) and biofilms. QS is a bacterial communication system to produce density-dependent response via chemical signalling that controls pathogenesis and biofilms formation. Leaves of green tea are used worldwide as beverage which is also known for its broad-spectrum therapeutic efficacy.
View Article and Find Full Text PDFSci Rep
November 2014
Division of Genetics and Molecular Biology, Institute of Biological Sciences, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia.
N-acylhomoserine lactone (AHL)-based quorum sensing (QS) is important for the regulation of proteobacterial virulence determinants. Thus, the inhibition of AHL synthases offers non-antibiotics-based therapeutic potentials against QS-mediated bacterial infections. In this work, functional AHL synthases of Pseudomonas aeruginosa LasI and RhlI were heterologously expressed in an AHL-negative Escherichia coli followed by assessments on their AHLs production using AHL biosensors and high resolution liquid chromatography-mass spectrometry (LCMS).
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