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Liu X, Liu Y, Zhao G, Zhang Y, Liu L, Wang J, Wang Y, Zhang S, Li X, Guo D, Wang P, Xu X. Biochemical Characterization of Arylamine N-acetyltransferases From Vibrio vulnificus. Front Microbiol 2021; 11:595083. [PMID: 33537010 PMCID: PMC7847940 DOI: 10.3389/fmicb.2020.595083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Accepted: 12/09/2020] [Indexed: 12/03/2022] Open
Abstract
Vibrio vulnificus is a zoonotic bacterium that is capable of causing highly lethal diseases in humans; this pathogen is responsible for 95% of all seafood-related deaths in the United States. Arylamine N-acetyltransferases (NAT, E.C. 2.3.1.5) is a major family of xenobiotic-metabolizing enzymes that can biotransform aromatic amine chemicals. In this research, to evaluate the effect of NAT on acetyl group transformation in arylamine antibiotics, we first used sequence alignment to study the structure of V. vulnificus NAT [(VIBVN)NAT]. The nat gene encodes a protein of 260 amino acids, which has an approximate molecular mass of 30 kDa. Then we purified recombinant (VIBVN)NAT and determined the enzyme activity by PNPA and DTNB methods. The DTNB method indicates that this prokaryotic NAT has a particular substrate specificity towards aromatic substrates. However, (VIBVN)NAT lost most of its activity after treatment with high concentrations of urea and H2O2. In addition, we also explored the stability of the enzyme at different temperatures and pH values. In analyzing the influence of metal ions, the enzyme activity was significantly inhibited by Zn2+ and Cu2+. The kinetic parameters Km and Vmax were determined using hydralazine, isoniazid, 4-amino salicylic acid, and 4-chloro-3-methylaniline as substrates, and the Tm, Tagg and size distribution of (VIBVN)NAT were observed. In particular, a molecular docking study on the structure of (VIBVN)NAT was conducted to understand its biochemical traits. These results showed that (VIBVN)NAT could acetylate various aromatic amine substrates and contribute to arylamine antibiotic resistance in V. vulnificus.
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Affiliation(s)
- Xinning Liu
- Marine Drug Screening and Evaluation Platform (QNLM), School of Medicine and Pharmacy, Ocean University of China, Qingdao, China.,Center for Innovation Marine Drug Screening & Evaluation, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao, China.,Institute of Bioinformatics and Medical Engineering, Jiangsu University of Technology, Changzhou, China
| | - Yuanchang Liu
- Quality Control Department, Qilu Children's Hospital of Shandong University, Jinan, China
| | - Guangjian Zhao
- Marine Drug Screening and Evaluation Platform (QNLM), School of Medicine and Pharmacy, Ocean University of China, Qingdao, China
| | - Yidan Zhang
- Marine Drug Screening and Evaluation Platform (QNLM), School of Medicine and Pharmacy, Ocean University of China, Qingdao, China
| | - Lu Liu
- Marine Drug Screening and Evaluation Platform (QNLM), School of Medicine and Pharmacy, Ocean University of China, Qingdao, China
| | - Juan Wang
- Marine Drug Screening and Evaluation Platform (QNLM), School of Medicine and Pharmacy, Ocean University of China, Qingdao, China
| | - Yifan Wang
- College of Food Science and Engineering, Ocean University of China, Qingdao, China
| | - Siyu Zhang
- School of Life Sciences, Lanzhou University, Lanzhou, China
| | - Xin Li
- School of Life Sciences, Lanzhou University, Lanzhou, China
| | - Dongliang Guo
- School of Information Science and Engineering, Yanshan University, Qinhuangdao, China
| | - Peng Wang
- College of Food Science and Engineering, Ocean University of China, Qingdao, China
| | - Ximing Xu
- Marine Drug Screening and Evaluation Platform (QNLM), School of Medicine and Pharmacy, Ocean University of China, Qingdao, China.,Center for Innovation Marine Drug Screening & Evaluation, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao, China.,Institute of Bioinformatics and Medical Engineering, Jiangsu University of Technology, Changzhou, China
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Xu X, Kubiak X, Dupret JM, Rodrigues-Lima F. Arylamine N-acetyltransferases: a structural perspective. Comments regarding the BJP paper by Zhou et al., 2013. Br J Pharmacol 2013; 171:279-80. [PMID: 24328723 DOI: 10.1111/bph.12273] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Affiliation(s)
- Ximing Xu
- Univ Paris Diderot, Sorbonne Paris Cité, Unité de Biologie Fonctionnelle et Adaptative, Paris, France
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Kubiak X, Li de la Sierra-Gallay I, Chaffotte AF, Pluvinage B, Weber P, Haouz A, Dupret JM, Rodrigues-Lima F. Structural and biochemical characterization of an active arylamine N-acetyltransferase possessing a non-canonical Cys-His-Glu catalytic triad. J Biol Chem 2013; 288:22493-505. [PMID: 23770703 DOI: 10.1074/jbc.m113.468595] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Arylamine N-acetyltransferases (NATs), a class of xenobiotic-metabolizing enzymes, catalyze the acetylation of aromatic amine compounds through a strictly conserved Cys-His-Asp catalytic triad. Each residue is essential for catalysis in both prokaryotic and eukaryotic NATs. Indeed, in (HUMAN)NAT2 variants, mutation of the Asp residue to Asn, Gln, or Glu dramatically impairs enzyme activity. However, a putative atypical NAT harboring a catalytic triad Glu residue was recently identified in Bacillus cereus ((BACCR)NAT3) but has not yet been characterized. We report here the crystal structure and functional characterization of this atypical NAT. The overall fold of (BACCR)NAT3 and the geometry of its Cys-His-Glu catalytic triad are similar to those present in functional NATs. Importantly, the enzyme was found to be active and to acetylate prototypic arylamine NAT substrates. In contrast to (HUMAN) NAT2, the presence of a Glu or Asp in the triad of (BACCR)NAT3 did not significantly affect enzyme structure or function. Computational analysis identified differences in residue packing and steric constraints in the active site of (BACCR)NAT3 that allow it to accommodate a Cys-His-Glu triad. These findings overturn the conventional view, demonstrating that the catalytic triad of this family of acetyltransferases is plastic. Moreover, they highlight the need for further study of the evolutionary history of NATs and the functional significance of the predominant Cys-His-Asp triad in both prokaryotic and eukaryotic forms.
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Affiliation(s)
- Xavier Kubiak
- Université Paris Diderot, Sorbonne Paris Cité, Unité de Biologie Fonctionnelle et Adaptative, CNRS EAC4413, 75013 Paris, France
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Kubiak X, Dairou J, Dupret JM, Rodrigues-Lima F. Crystal structure of arylamineN-acetyltransferases: insights into the mechanisms of action and substrate selectivity. Expert Opin Drug Metab Toxicol 2013; 9:349-62. [DOI: 10.1517/17425255.2013.742505] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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