Comamonas testosteroni (C. testosteroni) ATCC11996 is a gram negative bacterium which can use steroid as a carbon and energy source. 3,17β-hydroxysteroid dehydrogenase (3,17β-HSD) is a key enzyme for the degradation of steroid hormones in C. testosteroni. The LuxR regulation family is a group of regulatory proteins which play important role in gram negative bacterium. The luxr gene is located on 58 kb upstream of 3,17β-HSD gene with the opposite transcription orientation in the chromosomal DNA of C. testosteroni. An open reading frame of this putative luxr gene consists of 1125 bp and is translated into a protein containing 374 amino acids. The luxr gene was cloned into plasmid pK18 and plasmid pK-LuxR1 was obtained. E. coli HB101 was co-transformed by pK-LuxR1 and pUC912-10, pUC1128-5 or pUC3.2-4 (which contain βhsd gene and different length promoter, repeat sequences). The result of ELISA showed that LuxR protein is a negative regulator for 3,17β-HSD expression. The luxr gene in C. testosteroni was knock-out by homologous integration. 3,17β-HSD expression was increased in the mutant (C.T.-L-KO1) comparing to that in wild-type C. testosteroni (C.T.) after 0.5 mM testosterone induction. The mutant C.T.-L-KO1 and wild-type C. testosteroni were cultured at 27 °C and 37 °C. The result of growth curve proved that LuxR has also effect on the bacterial growth.
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http://dx.doi.org/10.1016/j.cbi.2017.03.002 | DOI Listing |
Appl Environ Microbiol
January 2025
Department of Biology, Indiana University, Bloomington, Indiana, USA.
The bacterial pathogen causes disease in coral species worldwide. The mechanisms of coral colonization, coral microbiome interactions, and virulence factor production are understudied. In other model species, virulence factors like biofilm formation, toxin secretion, and protease production are controlled through a density-dependent communication system called quorum sensing (QS).
View Article and Find Full Text PDFAppl Environ Microbiol
December 2024
State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, Shanghai, People's Republic of China.
Mildiomycin is a representative peptidyl nucleoside antibiotic and was first isolated from , which has been used as an important biological agent to control powdery mildew in plants. Despite its importance, the biosynthetic pathways and regulatory mechanisms remain to be fully elucidated. In this study, we identified MilO as a positive pathway-specific regulator of mildiomycin biosynthesis in the heterologous host .
View Article and Find Full Text PDFUnlabelled: is a Gram-negative opportunistic pathogen that poses a significant public health threat, particularly in healthcare settings. A key determinant of virulence is the regulated synthesis and release of extracellular products, which is controlled by a cell density-dependent signaling system known as quorum sensing (QS). uses a complex QS network, including two systems that rely on diffusible N-acylhomoserine lactone (AHL) signal molecules.
View Article and Find Full Text PDFMicrobiologyopen
December 2024
Departamento de Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Mexico City, Mexico.
Cereibacter sphaeroides has a quorum sensing (QS) system that has been partially characterized. Using a bioinformatic approach, six LuxR homologs and one homolog of the acylhomoserine lactone synthase were identified in this bacterium, including the previously characterized CerR and CerI proteins. This study focused on determining the roles of two LuxR homologs, CerM and CerN.
View Article and Find Full Text PDFLett Appl Microbiol
December 2024
School of Food Science and Engineering, Shaanxi University of Science & Technology, Xi'an 710021, China.
Vibrio alginolyticus, the causative agent of aquatic vertebrates and invertebrates, can cause severe infections (e.g. septicemia, gill necrosis, and surface ulcers) and high mortality in aquatic organisms, leading to serious economic losses in global aquaculture.
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