scholarly journals Cloning and identification of a new repressor of 3,17β-Hydroxysteroid dehydrogenase of Comamonas testosteroni

2021 ◽  
Author(s):  
Weiqi Xie ◽  
Qin Xia ◽  
Ling Chen ◽  
Guangming Xiong ◽  
Yuwei Gao ◽  
...  
Keyword(s):  
Hydroxysteroid Dehydrogenase ◽  
Comamonas Testosteroni

scholarly journals TeiR, a LuxR-Type Transcription Factor Required for Testosterone Degradation in Comamonas testosteroni

2004 ◽  
Vol 186 (5) ◽  
pp. 1430-1437 ◽  
Author(s):  
José Luis Pruneda-Paz ◽  
Mauricio Linares ◽  
Julio E. Cabrera ◽  
Susana Genti-Raimondi
Keyword(s):  
Hydroxysteroid Dehydrogenase ◽  
Nucleotide Sequence Analysis ◽  
Transcriptional Level ◽  
Comamonas Testosteroni ◽  
Acid Protein ◽  
Inducible Protein ◽  
Inducible Genes ◽  
Amino Acid Protein ◽  
Inducible Gene ◽  
Gene Mrna

ABSTRACT We have identified a new steroid-inducible gene (designated teiR [testosterone-inducible regulator]) in Comamonas testosteroni that is required for testosterone degradation. Nucleotide sequence analysis of teiR predicts a 391-amino-acid protein which shows homology between residues 327 and 380 (C-terminal domain) to the LuxR helix-turn-helix DNA binding domain and between residues 192 and 227 to the PAS sensor domain. This domain distribution resembles that described for TraR, a specific transcriptional regulator involved in quorum sensing in Agrobacterium tumefaciens. Analysis of the gene expression indicated that teiR is tightly controlled at the transcriptional level by the presence of testosterone in the culture medium. A teiR-disrupted mutant strain was completely unable to use testosterone as the sole carbon and energy source. In addition, the expression of several steroid-inducible genes was abolished in this mutant. Northern blot assays revealed that teiR is required for full expression of sip48-β-HSD gene mRNA (encoding a steroid-inducible protein of 48 kDa and 3β-17β-hydroxysteroid dehydrogenase) and also of other steroid degradation genes, including those encoding 3α-hydroxysteroid dehydrogenase, Δ5-3-ketoisomerase, 3-oxo-steroid Δ1-dehydrogenase, and 3-oxo-steroid Δ4-(5α)-dehydrogenase enzymes. Moreover, when teiR was provided to the teiR-disrupted strain in trans, the transcription level of these genes was restored. These results indicate that TeiR positively regulates the transcription of genes involved in the initial enzymatic steps of steroid degradation in C. testosteroni.

Characterization of 3,17β-hydroxysteroid dehydrogenase in Comamonas testosteroni

2015 ◽  
Vol 234 ◽  
pp. 221-228 ◽  
Author(s):  
Yuanhua Yu ◽  
Chuanzhi Liu ◽  
Baoxue Wang ◽  
Yanhong Li ◽  
Hao Zhang
Keyword(s):  
Hydroxysteroid Dehydrogenase ◽  
Comamonas Testosteroni

scholarly journals Cloning and Identification of a New Repressor of 3,17β-Hydroxysteroid Dehydrogenase of Comamonas Testosteroni

2021 ◽  
Author(s):  
Weiqi Xie ◽  
Qin Xia ◽  
Ling Chen ◽  
Guangming Xiong ◽  
Yuwei Gao ◽  
...  
Keyword(s):  
Mutant Strain ◽  
Function Analysis ◽  
Gene Knockout ◽  
Carbon Sources ◽  
Hydroxysteroid Dehydrogenase ◽  
Regulation Mechanism ◽  
Comamonas Testosteroni ◽  
Loss Of Function ◽  
Mobility Shift ◽  
Environmental Signals

Abstract 3,17β-hydroxysteroid dehydrogenase (3,17β-HSD) is a key enzyme that can degrade steroid compounds 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 were 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 acts as repressors of 3,17β-HSD is still unknown. In the present study, we cloned the second TetR gene and analyzed the regulation 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 knockout has 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, suggesting the mutant can efficiently degrade steroids as carbon sources. The mutant generated in this study can be used to treat environmental pollution caused by steroid hormones.

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