Background: 3,17β-hydroxysteroid dehydrogenase (3,17β-HSD) is a key enzyme in the metabolic pathway for steroid compounds catabolism in Comamonas testosteroni. Tetracycline repressor (TetR) family, repressors existing in most microorganisms, may play key roles in regulating the expression of 3,17β-HSD. Previous reports showed that three tetR genes are located in the contig58 of C. testosteroni ATCC 11996 (GenBank: AHIL01000049.1), among which the first tetR gene encoded a potential repressor of 3,17β-HSD by sensing environmental signals. However, whether the other proposed tetR genes act as repressors of 3,17β-HSD are still unknown.
Methods And Results: In the present study, we cloned the second tetR gene and analyzed the regulatory mechanism of the protein on 3,17β-HSD using electrophoretic mobility shift assay (EMSA), gold nanoparticles (AuNPs)-based assay, and loss-of-function analysis. The results showed that the second tetR gene was 660-bp, encoding a 26 kD protein, which could regulate the expression of 3,17β-HSD gene via binding to the conserved consensus sequences located 1100-bp upstream of the 3,17β-HSD gene. Furthermore, the mutant strain of C. testosteroni with the second tetR gene knocked-out mutant expresses good biological genetic stability, and the expression of 3,17β-HSD in the mutant strain is slightly higher than that in the wild type under testosterone induction.
Conclusions: The second tetR gene acts as a negative regulator in 3,17β-HSD expression, and the mutant has potential application in bioremediation of steroids contaminated environment.
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http://dx.doi.org/10.1007/s11033-021-06566-9 | DOI Listing |
Front Pediatr
January 2025
Department of Hematology, Aerospace Center Hospital, Beijing, China.
Introduction: Hypervirulent carbapenem-resistant Klebsiella pneumoniae (hv-CRKP) poses an increasing public health risk due to its high treatment difficulty and associated mortality, especially in bone marrow transplant (BMT) patients. The emergence of strains with multiple resistance mechanisms further complicates the management of these infections.
Methods: We isolated and characterized a novel ST11-KL64 hv-CRKP strain from a pediatric bone marrow transplantation patient.
J Hazard Mater
January 2025
State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 211135, China.
Bioaugmentation offers an effective strategy for the bioremediation of petroleum-contaminated soils. However, little is known about petroleum hydrocarbons (PHs) degradation with thermophilic consortium application under high temperature. A microcosm was established to study hydrocarbons degradation, microbial communities and functional genes response using a thermophilic petroleum-degrading consortium HT.
View Article and Find Full Text PDFBiotechnol Adv
January 2025
Department of Urology, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710004, China; Institute of Medical Engineering, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an 710061, China. Electronic address:
Gene circuits, which are genetically engineered systems designed to regulate gene expression, are emerging as powerful tools in disease theranostics, especially in mammalian cells. This review explores the latest advances in the design and application of gene circuits for detecting and treating various diseases. Synthetic gene circuits, inspired by electronic systems, offer precise control over therapeutic gene activity, allowing for real-time, user-defined responses to pathological signals.
View Article and Find Full Text PDFInfect Drug Resist
December 2024
Subdean Office, Anqing First People's Hospital of Anhui Medical University, Anqing City, Anhui Province, People's Republic of China.
Purpose: To evaluate the clinical characteristics, antimicrobial resistance (AMR) phenotypes and genotypes, and homology features of carbapenem-resistant (CRAB) in intensive care unit (ICU) and to provide basis for effectively prevention, control and treatment of nosocomial infections caused by CRAB.
Methods: A total of 39 CRAB strains isolated from hospitalized patients in the ICU and neurosurgical ICU (NICU) between 2020 and 2023 were subjected to antimicrobial susceptibility testing and whole-genome sequencing (WGS). Virulence factor genes (VFGs), antimicrobial resistance genes (ARGs), multilocus sequencing typing (MLST), complete genome multilocus sequencing typing (cgMLST), average nucleotide identity (ANI), and single nucleotide polymorphism (SNP) analyses were performed using WGS.
Nat Commun
December 2024
Department of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstrasse 190, Zurich, CH-8057, Switzerland.
Transcription factor binding sites (TFBSs) are important sources of evolutionary innovations. Understanding how evolution navigates the sequence space of such sites can be achieved by mapping TFBS adaptive landscapes. In such a landscape, an individual location corresponds to a TFBS bound by a transcription factor.
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