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Alkhzem A, Woodman TJ, Blagbrough IS. Multinuclear Nuclear Magnetic Resonance Spectroscopy Is Used to Determine Rapidly and Accurately the Individual p K a Values of 2-Deoxystreptamine, Neamine, Neomycin, Paromomycin, and Streptomycin. ACS OMEGA 2021; 6:2824-2835. [PMID: 33553900 PMCID: PMC7860104 DOI: 10.1021/acsomega.0c05138] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Accepted: 12/21/2020] [Indexed: 05/13/2023]
Abstract
Unambiguous assignments have been made for each individual pK a value of the amino group and guanidine substituents on 2-deoxystreptamine, neamine, neomycin, paromomycin, and streptomycin by pH-titration evaluation of their 1H, 13C, and 15N (by 1H-15N heteronuclear multiple-bond correlation (HMBC) spectra) NMR chemical shifts (δXs) as the reporter nuclei. These data require minor revisions of the literature data in terms of the assignment order for neomycin and paromomycin. In situ titrations and NMR spectroscopy are shown to be a powerful combination for rapidly (minutes) obtaining each distinct pK a value of the similar amine and guanidine functional groups, which decorate aminoglycoside antibiotics.
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Abstract
Allostery is a ubiquitous biological regulatory process in which distant binding sites within a protein or enzyme are functionally and thermodynamically coupled. Allosteric interactions play essential roles in many enzymological mechanisms, often facilitating formation of enzyme-substrate complexes and/or product release. Thus, elucidating the forces that drive allostery is critical to understanding the complex transformations of biomolecules. Currently, a number of models exist to describe allosteric behavior, taking into account energetics as well as conformational rearrangements and fluctuations. In the following Review, we discuss the use of solution NMR techniques designed to probe allosteric mechanisms in enzymes. NMR spectroscopy is unequaled in its ability to detect structural and dynamical changes in biomolecules, and the case studies presented herein demonstrate the range of insights to be gained from this valuable method. We also provide a detailed technical discussion of several specialized NMR experiments that are ideally suited for the study of enzymatic allostery.
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Affiliation(s)
- George P. Lisi
- Department of Chemistry, Yale University, New Haven, CT 06520
| | - J. Patrick Loria
- Department of Chemistry, Yale University, New Haven, CT 06520
- Department of Molecular Biophysics & Biochemistry, Yale University, New Haven, CT 06520
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Favrot L, Blanchard JS, Vergnolle O. Bacterial GCN5-Related N-Acetyltransferases: From Resistance to Regulation. Biochemistry 2016; 55:989-1002. [PMID: 26818562 DOI: 10.1021/acs.biochem.5b01269] [Citation(s) in RCA: 123] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The GCN5-related N-acetyltransferases family (GNAT) is an important family of proteins that includes more than 100000 members among eukaryotes and prokaryotes. Acetylation appears as a major regulatory post-translational modification and is as widespread as phosphorylation. N-Acetyltransferases transfer an acetyl group from acetyl-CoA to a large array of substrates, from small molecules such as aminoglycoside antibiotics to macromolecules. Acetylation of proteins can occur at two different positions, either at the amino-terminal end (αN-acetylation) or at the ε-amino group (εN-acetylation) of an internal lysine residue. GNAT members have been classified into different groups on the basis of their substrate specificity, and in spite of a very low primary sequence identity, GNAT proteins display a common and conserved fold. This Current Topic reviews the different classes of bacterial GNAT proteins, their functions, their structural characteristics, and their mechanism of action.
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Affiliation(s)
- Lorenza Favrot
- Department of Biochemistry, Albert Einstein College of Medicine , 1300 Morris Park Avenue, Bronx, New York 10461, United States
| | - John S Blanchard
- Department of Biochemistry, Albert Einstein College of Medicine , 1300 Morris Park Avenue, Bronx, New York 10461, United States
| | - Olivia Vergnolle
- Department of Biochemistry, Albert Einstein College of Medicine , 1300 Morris Park Avenue, Bronx, New York 10461, United States
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Jing X, Serpersu EH. Solvent Reorganization Plays a Temperature-Dependent Role in Antibiotic Selection by a Thermostable Aminoglycoside Nucleotidyltransferase-4′. Biochemistry 2014; 53:5544-50. [DOI: 10.1021/bi5006283] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Xiaomin Jing
- Department
of Biochemistry and Cellular and Molecular Biology, The University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Engin H. Serpersu
- Graduate
School of Genome Science and Technology, The University of Tennessee and Oak Ridge National Laboratories, Knoxville, Tennessee 37996, United States
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Serpersu EH, Norris AL. Effect of protein dynamics and solvent in ligand recognition by promiscuous aminoglycoside-modifying enzymes. Adv Carbohydr Chem Biochem 2012; 67:221-48. [PMID: 22794185 DOI: 10.1016/b978-0-12-396527-1.00005-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- Engin H Serpersu
- Department of Biochemistry, Cellular and Molecular Biology, The University of Tennessee, Knoxville, TN, USA
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Vong K, Auclair K. Understanding and overcoming aminoglycoside resistance caused by N-6'-acetyltransferase. MEDCHEMCOMM 2012; 3:397-407. [PMID: 28018574 PMCID: PMC5179255 DOI: 10.1039/c2md00253a] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Aminoglycosides occupy a special niche amongst antibiotics in part because of their broad spectrum of action. Bacterial resistance is however menacing to render these drugs obsolete. A significant amount of work has been devoted to understand and overcome aminoglycoside resistance. This mini-review will discuss aminoglycoside-modifying enzymes (AMEs), with a special emphasis on the efforts to comprehend and block resistance caused by aminoglycoside 6'-N-acetyltransferase (AAC(6')).
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Affiliation(s)
- Kenward Vong
- Department of Chemistry, McGill University, 801 Sherbrooke Street West, Montréal, Québec, Canada H3A 2K6
| | - Karine Auclair
- Department of Chemistry, McGill University, 801 Sherbrooke Street West, Montréal, Québec, Canada H3A 2K6
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Norris AL, Özen C, Serpersu EH. Thermodynamics and Kinetics of Association of Antibiotics with the Aminoglycoside Acetyltransferase (3)-IIIb, a Resistance-Causing Enzyme. Biochemistry 2010; 49:4027-35. [DOI: 10.1021/bi100155j] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Adrianne L. Norris
- Department of Biochemistry and Cellular and Molecular Biology, The University of Tennessee, Knoxville, Tennessee 37996
| | - Can Özen
- Department of Biotechnology and Central Laboratory Molecular Biology and Biotechnology R&D Center, Middle East Technical University, Ankara, Turkey
| | - Engin H. Serpersu
- Department of Biochemistry and Cellular and Molecular Biology, The University of Tennessee, Knoxville, Tennessee 37996
- Graduate School of Genome Science and Technology, The University of Tennessee and Oak Ridge National Laboratories, Knoxville, Tennessee 37996, and Bioscience Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831
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8
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Revuelta J, Vacas T, Torrado M, Corzana F, Gonzalez C, Jiménez-Barbero J, Menendez M, Bastida A, Asensio JL. NMR-based analysis of aminoglycoside recognition by the resistance enzyme ANT(4'): the pattern of OH/NH3(+) substitution determines the preferred antibiotic binding mode and is critical for drug inactivation. J Am Chem Soc 2008; 130:5086-103. [PMID: 18366171 DOI: 10.1021/ja076835s] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The most significant mechanism of bacterial resistance to aminoglycosides is the enzymatic inactivation of the drug. Herein, we analyze several key aspects of the aminoglycoside recognition by the resistance enzyme ANT(4') from Staphylococcus aureus, employing NMR complemented with site-directed mutagenesis experiments and measurements of the enzymatic activity on newly synthesized kanamycin derivatives. From a methodological perspective, this analysis provides the first example reported for the use of transferred NOE (trNOE) experiments in the analysis of complex molecular recognition processes, characterized by the existence of simultaneous binding events of the ligand to different regions of a protein receptor. The obtained results show that, in favorable cases, these overlapping binding processes can be isolated employing site-directed mutagenesis and then independently analyzed. From a molecular recognition perspective, this work conclusively shows that the enzyme ANT(4') displays a wide tolerance to conformational variations in the drug. Thus, according to the NMR data, kanamycin-A I/II linkage exhibits an unusual anti-Psi orientation in the ternary complex, which is in qualitative agreement with the previously reported crystallographic complex. In contrast, closely related, kanamycin-B is recognized by the enzyme in the syn-type arrangement for both glycosidic bonds. This observation together with the enzymatic activity displayed by ANT(4') against several synthetic kanamycin derivatives strongly suggests that the spatial distribution of positive charges within the aminoglycoside scaffold is the key feature that governs its preferred binding mode to the protein catalytic region and also the regioselectivity of the adenylation reaction. In contrast, the global shape of the antibiotic does not seem to be a critical factor. This feature represents a qualitative difference between the target A-site RNA and the resistance enzyme ANT(4') as aminoglycoside receptors.
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Affiliation(s)
- Julia Revuelta
- Instituto de Química Orgánica General (CSIC), Madrid 28006, Spain
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Affiliation(s)
- Bert Willis
- Department of Chemistry, Clemson University, Clemson, SC 29634, USA
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Wang J, Li J, Chen HN, Chang H, Tanifum CT, Liu HH, Czyryca PG, Chang CWT. Glycodiversification for the Optimization of the Kanamycin Class Aminoglycosides. J Med Chem 2005; 48:6271-85. [PMID: 16190754 DOI: 10.1021/jm050368c] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In an effort to optimize the antibacterial activity of kanamycin class aminoglycoside antibiotics, we have accomplished the synthesis and antibacterial assay of new kanamycin B analogues. A rationale-based glycodiversification strategy was employed. The activity of the lead is comparable to that of commercially available kanamycin. These new members, however, were found to be inactive against aminoglycoside resistant bacteria. Molecular modeling was used to provide the explanation. Thus, a new strategy for structural modifications of kanamycin class aminoglycosides is suggested.
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Affiliation(s)
- Jinhua Wang
- Department of Chemistry and Biochemistry, Utah State University, 0300 Old Main Hill, Logan, Utah 84322-0300, USA
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Rai R, McAlexander I, Chang CWT. SYNTHETIC GLYCODIVERSIFICATION. FROM AMINOSUGARS TO AMINOGLYCOSIDE ANTIBIOTICS. A REVIEW. ORG PREP PROCED INT 2005. [DOI: 10.1080/00304940509354969] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Affiliation(s)
- Sophie Magnet
- Department of Biochemistry, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, New York 10461, USA
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Vetting MW, Magnet S, Nieves E, Roderick SL, Blanchard JS. A Bacterial Acetyltransferase Capable of Regioselective N-Acetylation of Antibiotics and Histones. ACTA ACUST UNITED AC 2004; 11:565-73. [PMID: 15123251 DOI: 10.1016/j.chembiol.2004.03.017] [Citation(s) in RCA: 101] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2003] [Revised: 01/27/2004] [Accepted: 01/30/2004] [Indexed: 11/27/2022]
Abstract
The Salmonella enterica chromosomally encoded AAC(6')-Iy has been shown to confer broad aminoglycoside resistance in strains in which the structural gene is expressed. The three-dimensional structures reported place the enzyme in the large Gcn5-related N-acetyltransferase (GNAT) superfamily. The structure of the CoA-ribostamycin ternary complex allows us to propose a chemical mechanism for the reaction, and comparison with the Mycobacterium tuberculosis AAC(2')-CoA-ribostamycin complex allows us to define how regioselectivity of acetylation is achieved. The AAC(6')-Iy dimer is most structurally similar to the Saccharomyces cerevisiae Hpa2-encoded histone acetyltransferase. We demonstrate that AAC(6')-Iy catalyzes both acetyl-CoA-dependent self-alpha-N-acetylation and acetylation of eukaryotic histone proteins and the human histone H3 N-terminal peptide. These structural and catalytic similarities lead us to propose that chromosomally encoded bacterial acetyltransferases, including those functionally identified as aminoglycoside acetyltransferases, are the evolutionary progenitors of the eukaryotic histone acetyltransferases.
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Affiliation(s)
- Matthew W Vetting
- Department of Biochemistry, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461 USA
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Lesniak W, Mc Laren J, Harris WR, Pecoraro VL, Schacht J. An isocratic separation of underivatized gentamicin components, 1H NMR assignment and protonation pattern. Carbohydr Res 2003; 338:2853-62. [PMID: 14667706 DOI: 10.1016/j.carres.2003.08.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
A simple method for the separation of the major components of commercial gentamicin sulfate (C-1, C-1a, C-2, C-2a) by high-performance liquid chromatography (HPLC) on an analytical and a semipreparative scale was developed. The method utilized ion-pair reversed-phase chromatography, isocratic elution with an aqueous solution containing 9% trifluoroacetic acid and 2.5% acetonitrile as the mobile phase at a flow rate of 2 and 9 mL/min for analytical and semipreparative columns, respectively. Detection was carried out at 213 nm without derivatization. The protonation pattern of the separated gentamicins was determined by potentiometry and 15N and 1H NMR. The full proton NMR assignment for gentamicin C-1 was obtained through the use of 1H 1D and 2D 1H-1H COSY measurements.
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Affiliation(s)
- Wojciech Lesniak
- Department of Otolaryngology, Kresge Hearing Research Institute, University of Michigan, 1331 E Ann, Ann Arbor, MI 48109-0506, USA
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Draker KA, Northrop DB, Wright GD. Kinetic mechanism of the GCN5-related chromosomal aminoglycoside acetyltransferase AAC(6')-Ii from Enterococcus faecium: evidence of dimer subunit cooperativity. Biochemistry 2003; 42:6565-74. [PMID: 12767240 DOI: 10.1021/bi034148h] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The aminoglycoside 6'-N-acetyltransferase AAC(6')-Ii from Enterococcus faecium is an important microbial resistance determinant and a member of the GCN5-related N-acetyltransferase (GNAT) superfamily. We report here the further characterization of this enzyme in terms of the kinetic mechanism of acetyl transfer and identification of rate-contributing step(s) in catalysis, as well as investigations into the binding of both acetyl-CoA and aminoglycoside substrates to the AAC(6')-Ii dimer. Product and dead-end inhibition studies revealed that AAC(6')-Ii follows an ordered bi-bi ternary complex mechanism with acetyl-CoA binding first followed by antibiotic. Solvent viscosity studies demonstrated that aminoglycoside binding and product release govern the rate of acetyl transfer, as evidenced by changes in both the k(cat)/K(b) for aminoglycoside and k(cat), respectively, with increasing solvent viscosity. Solvent isotope effects were consistent with our viscosity studies that diffusion-controlled processes and not the chemical step were rate-limiting in drug modification. The patterns of partial and mixed inhibition observed during our mechanistic studies were followed up by investigating the possibility of subunit cooperativity in the AAC(6')-Ii dimer. Through the use of AAC-Trp(164) --> Ala, an active mutant which exists as a monomer in solution, the partial nature of the competitive inhibition observed in wild-type dead-end inhibition studies was alleviated. Isothermal titration calorimetry studies also indicated two nonequivalent antibiotic binding sites for the AAC(6')-Ii dimer but only one binding site for the Trp(164) --> Ala mutant. Taken together, these results demonstrate subunit cooperativity in the AAC(6')-Ii dimer, with possible relevance to other oligomeric members of the GNAT superfamily.
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Affiliation(s)
- Kari-ann Draker
- Antimicrobial Research Centre, Department of Biochemistry, McMaster University, 1200 Main Street West, Ontario L8N 3Z5, Canada
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Stead DA. Current methodologies for the analysis of aminoglycosides. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL SCIENCES AND APPLICATIONS 2000; 747:69-93. [PMID: 11103900 DOI: 10.1016/s0378-4347(00)00133-x] [Citation(s) in RCA: 153] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The aminoglycosides are a large and diverse class of antibiotics that characteristically contain two or more aminosugars linked by glycosidic bonds to an aminocyclitol component. Structures are presented for over 30 of the most important members of this family of compounds. The use of aminoglycosides in clinical and veterinary medicine and in agriculture is described. Qualitative methods for aminoglycoside analysis include X-ray crystallography, nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry (MS). The major part of this article comprises a comprehensive review of quantitative methods for the determination of aminoglycosides. These are microbiological assay, radiochemical assay, radioimmunoassay, enzyme immunoassay, fluoroimmunoassay and other immunoassays, spectrophotometric and other non-separative methods, gas chromatography (GC), thin-layer chromatography (TLC), high-performance liquid chromatography (HPLC), and capillary electrophoresis (CE). Simple spectrophotometric methods may be adequate for the assay of bulk pharmaceuticals and their formulations. Microbiological assays make useful semi-quantitative screening tests for the analysis of veterinary drug residues in food, but rapid enzyme immunoassays are more suitable for accurate measurements of aminoglycosides in complex matrices. Automated immunoassays are the most appropriate methods for serum aminoglycoside determinations during therapeutic drug monitoring. HPLC techniques provide the specificity and sensitivity required for pharmacokinetic and other research studies, while HPLC-MS is employed for the confirmation of veterinary drug residues. The potential for further development of chromatographic and CE methods for the analysis of biological samples is outlined.
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Thompson PR, Schwartzenhauer J, Hughes DW, Berghuis AM, Wright GD. The COOH terminus of aminoglycoside phosphotransferase (3')-IIIa is critical for antibiotic recognition and resistance. J Biol Chem 1999; 274:30697-706. [PMID: 10521458 DOI: 10.1074/jbc.274.43.30697] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The aminoglycoside phosphotransferases (APHs) are widely distributed among pathogenic bacteria and are employed to covalently modify, and thereby detoxify, the clinically relevant aminoglycoside antibiotics. The crystal structure for one of these aminoglycoside kinases, APH(3')-IIIa, has been determined in complex with ADP and analysis of the electrostatic surface potential indicates that there is a large anionic depression present adjacent to the terminal phosphate group of the nucleotide. This region also includes a conserved COOH-terminal alpha-helix that contains the COOH-terminal residue Phe(264). We report here mutagenesis and computer modeling studies aimed at examining the mode of aminoglycoside binding to APH(3')-IIIa. Specifically, seven site mutants were studied, five from the COOH-terminal helix (Asp(261), Glu(262), and Phe(264)), and two additional residues that line the wall of the anionic depression (Tyr(55) and Arg(211)). Using a molecular modeling approach, six ternary complexes of APH(3')-IIIa.ATP with the antibiotics, kanamycin, amikacin, butirosin, and ribostamycin were independently constructed and these agree well with the mutagenesis data. The results obtained show that the COOH-terminal carboxylate of Phe(264) is critical for proper function of the enzyme. Furthermore, these studies demonstrate that there exists multiple binding modes for the aminoglycosides, which provides a molecular basis for the broad substrate- and regiospecificity observed for this enzyme.
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Affiliation(s)
- P R Thompson
- Antimicrobial Research Centre, McMaster University, 1200 Main Street West, Hamilton, Ontario, L8N 3Z5 Canada
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Wybenga-Groot LE, Draker K, Wright GD, Berghuis AM. Crystal structure of an aminoglycoside 6'-N-acetyltransferase: defining the GCN5-related N-acetyltransferase superfamily fold. Structure 1999; 7:497-507. [PMID: 10378269 DOI: 10.1016/s0969-2126(99)80066-5] [Citation(s) in RCA: 118] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BACKGROUND The predominant mechanism of antibiotic resistance employed by pathogenic bacteria against the clinically used aminoglycosides is chemical modification of the drug. The detoxification reactions are catalyzed by enzymes that promote either the phosphorylation, adenylation or acetylation of aminoglycosides. Structural studies of these aminoglycoside-modifying enzymes may assist in the development of therapeutic agents that could circumvent antibiotic resistance. In addition, such studies may shed light on the development of antibiotic resistance and the evolution of different enzyme classes. RESULTS The crystal structure of the aminoglycoside-modifying enzyme aminoglycoside 6'-N-acetyltransferase type li (AAC(6')-li) in complex with the cofactor acetyl coenzyme A has been determined at 2.7 A resolution. The structure establishes that this acetyltransferase belongs to the GCN5-related N-acetyltransferase superfamily, which includes such enzymes as the histone acetyltransferases GCN5 and Hat1. CONCLUSIONS Comparison of the AAC(6')-li structure with the crystal structures of two other members of this superfamily, Serratia marcescens aminoglycoside 3-N-acetyltransferase and yeast histone acetyltransferase Hat1, reveals that of the 84 residues that are structurally similar, only three are conserved and none can be implicated as catalytic residues. Despite the negligible sequence identity, functional studies show that AAC(6')-li possesses protein acetylation activity. Thus, AAC(6')-li is both a structural and functional homolog of the GCN5-related histone acetyltransferases.
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Affiliation(s)
- L E Wybenga-Groot
- Department of Biochemistry, McMaster University, Hamilton, ON, Canada
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Bush K, Miller GH. Bacterial enzymatic resistance: beta-lactamases and aminoglycoside-modifying enzymes. Curr Opin Microbiol 1998; 1:509-15. [PMID: 10066532 DOI: 10.1016/s1369-5274(98)80082-9] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Numerous novel beta-lactamases and aminoglycoside-modifying enzymes with altered substrate profiles continue to be identified. Plasmid-mediated transmission of many of these enzymes readily occurs due to inclusion of the encoding genes in mobile gene cassettes. Recent crystallographic determinations of the structures of metallo-beta-lactamases and aminoglycoside-modifying enzymes provide the opportunity for the rational design of inhibitors.
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Affiliation(s)
- K Bush
- RW Johnson Pharmaceutical Research Institute, 1000 Route 202, Raritan NJ 08869, USA.
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