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Kudo F, Tsuboi K, Ikezaki M, Nagayama D, Kawamura K, Ando T, Miyanaga A, Eguchi T. The Post-Polyketide Synthase Modification Mechanism in Hitachimycin Biosynthesis. Chembiochem 2024; 25:e202400405. [PMID: 38849317 DOI: 10.1002/cbic.202400405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2024] [Revised: 06/06/2024] [Accepted: 06/07/2024] [Indexed: 06/09/2024]
Abstract
Hitachimycin is a bicyclic macrolactam antibiotic with (S)-β-phenylalanine (β-Phe) at the starter position of the polyketide skeleton. While the enzymes that recognize β-amino acids, modify the aminoacyl groups, and transfer the resultant dipeptide groups to the acyl carrier protein domains of polyketide synthases (PKSs) have been studied extensively, the post-PKS modification mechanism responsible for constructing the unique bicyclic structure of hitachimycin remains elusive. In this study, we first inactivated six genes encoding putative post-PKS modification enzymes, namely hitM1 to hitM6, in Streptomyces scabrisporus to determine their involvement in hitachimycin biosynthesis. The ΔhitM4 strain accumulated an all-trans-2,4,6,8,18-pentaene macrolactam, which was confirmed as a true intermediate in hitachimycin biosynthesis by cellular feeding experiments, and appears to be the initial intermediate in the post-PKS modification pathway. The ΔhitM1 strain accumulated 10-O-demethyl-10-oxohitachimycin (M1-A). In enzymatic experiments, M1-A was reduced by the NAD(P)H-dependent reductase HitM1 in the presence of NADPH. The product of the reaction catalyzed by HitM1 was converted to hitachimycin by the methyltransferase HitM6. We thus propose a plausible post-PKS modification mechanism for the biosynthesis of hitachimycin.
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Affiliation(s)
- Fumitaka Kudo
- Department of Chemistry, Tokyo Institute of Technology, 2-12-1 Meguro-ku, O-okayama, Tokyo, 152-8551, Japan
| | - Kazuma Tsuboi
- Department of Chemistry, Tokyo Institute of Technology, 2-12-1 Meguro-ku, O-okayama, Tokyo, 152-8551, Japan
| | - Mutsumi Ikezaki
- Department of Chemistry, Tokyo Institute of Technology, 2-12-1 Meguro-ku, O-okayama, Tokyo, 152-8551, Japan
| | - Daiki Nagayama
- Department of Chemistry, Tokyo Institute of Technology, 2-12-1 Meguro-ku, O-okayama, Tokyo, 152-8551, Japan
| | - Koichi Kawamura
- Department of Chemistry, Tokyo Institute of Technology, 2-12-1 Meguro-ku, O-okayama, Tokyo, 152-8551, Japan
| | - Taishi Ando
- Department of Chemistry, Tokyo Institute of Technology, 2-12-1 Meguro-ku, O-okayama, Tokyo, 152-8551, Japan
| | - Akimasa Miyanaga
- Department of Chemistry, Tokyo Institute of Technology, 2-12-1 Meguro-ku, O-okayama, Tokyo, 152-8551, Japan
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan
| | - Tadashi Eguchi
- Department of Chemistry, Tokyo Institute of Technology, 2-12-1 Meguro-ku, O-okayama, Tokyo, 152-8551, Japan
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Kim H, Mi HTN, Ahn JH, Lee JS, Eser BE, Choi J, Han J. Glycoside-metabolizing oxidoreductase D3dgpA from human gut bacterium. Front Bioeng Biotechnol 2024; 12:1413854. [PMID: 39007053 PMCID: PMC11239390 DOI: 10.3389/fbioe.2024.1413854] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2024] [Accepted: 05/20/2024] [Indexed: 07/16/2024] Open
Abstract
The Gfo/Idh/MocA family enzyme DgpA was known to catalyze the regiospecific oxidation of puerarin to 3"-oxo-puerarin in the presence of 3-oxo-glucose. Here, we discovered that D3dgpA, dgpA cloned from the human gut bacterium Dorea sp. MRG-IFC3, catalyzed the regiospecific oxidation of various C-/O-glycosides, including puerarin, in the presence of methyl β-D-3-oxo-glucopyranoside. While C-glycosides were converted to 3"- and 2"-oxo-products by D3dgpA, O-glycosides resulted in the formation of aglycones and hexose enediolone from the 3"-oxo-products. From DFT calculations, it was found that isomerization of 3"-oxo-puerarin to 2"-oxo-puerarin required a small activation energy of 9.86 kcal/mol, and the O-glycosidic bond cleavage of 3"-oxo-products was also thermodynamically favored with a small activation energy of 3.49 kcal/mol. In addition, the reaction mechanism of D3dgpA was discussed in comparison to those of Gfo/Idh/MocA and GMC family enzymes. The robust reactivity of D3dgpA was proposed as a new general route for derivatization of glycosides.
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Affiliation(s)
- Heji Kim
- Metalloenzyme Research Group and Department of Plant Science and Technology, Chung-Ang University, Anseong, Republic of Korea
| | - Huynh Thi Ngoc Mi
- Metalloenzyme Research Group and Department of Plant Science and Technology, Chung-Ang University, Anseong, Republic of Korea
| | - Joong-Hoon Ahn
- Department of Integrative Bioscience and Biotechnology, Bio/Molecular Informatics Center, Konkuk University, Seoul, Republic of Korea
| | - Jong Suk Lee
- Bio Industry Department, Gyeonggido Business and Science Accelerator (GBSA), Suwon, Gyeonngi-do, Republic of Korea
| | - Bekir Engin Eser
- Department of Biological and Chemical Engineering, Aarhus University, Aarhus, Denmark
| | - Jongkeun Choi
- Department of Chemical Engineering, Chungwoon University, Incheon, Republic of Korea
| | - Jaehong Han
- Metalloenzyme Research Group and Department of Plant Science and Technology, Chung-Ang University, Anseong, Republic of Korea
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Kitaoka M, Takano A, Takahashi M, Yamakawa Y, Fushinobu S, Yoshida N. Molecular Basis of Absorption at 340 nm of 3-Ketoglucosides under Alkaline Conditions. J Appl Glycosci (1999) 2024; 71:9-13. [PMID: 38799412 PMCID: PMC11116085 DOI: 10.5458/jag.jag.jag-2023_0014] [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: 10/19/2023] [Accepted: 11/17/2023] [Indexed: 05/29/2024] Open
Abstract
Transient absorption at 340 nm under alkaline conditions has long been used to detect the presence of 3-keto-O-glycosides without understanding the molecular basis of the absorbance. The time course of A340 nm for the alkaline treatment of 3-ketolevoglucosan, an intramolecular 3-keto-O-glycoside, was investigated to identify the three products generated through alkaline treatment. By comparing the spectra of these compounds under neutral and alkaline conditions, we identified 1,5-anhydro-D-erythro-hex-1-en-3-ulose (2-hydroxy-3-keto-D-glucal) as being the compound responsible for the absorption.
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Affiliation(s)
| | - Ayu Takano
- Faculty of Agriculture, Niigata University
| | - Mei Takahashi
- Department of Biotechnology, The University of Tokyo
| | | | - Shinya Fushinobu
- Department of Biotechnology, The University of Tokyo
- Collaborative Research Institute for Innovative Microbiology, The University of Tokyo
| | - Nobuyuki Yoshida
- Department of Engineering, Graduate School of Integrated Science and Technology, Shizuoka University
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Younus I, Kochkina S, Choi CC, Sun W, Ford RC. ATP-Binding Cassette Transporters: Snap-on Complexes? Subcell Biochem 2022; 99:35-82. [PMID: 36151373 DOI: 10.1007/978-3-031-00793-4_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
ATP-binding cassette (ABC) transporters are one of the largest families of membrane proteins in prokaryotic organisms. Much is now understood about the structure of these transporters and many reviews have been written on that subject. In contrast, less has been written on the assembly of ABC transporter complexes and this will be a major focus of this book chapter. The complexes are formed from two cytoplasmic subunits that are highly conserved (in terms of their primary and three-dimensional structures) across the whole family. These ATP-binding subunits give rise to the name of the family. They must assemble with two transmembrane subunits that will typically form the permease component of the transporter. The transmembrane subunits have been found to be surprisingly diverse in structure when the whole family is examined, with seven distinct folds identified so far. Hence nucleotide-binding subunits appear to have been bolted on to a variety of transmembrane platforms during evolution, leading to a greater variety in function. Furthermore, many importers within the family utilise a further external substrate-binding component to trap scarce substrates and deliver them to the correct permease components. In this chapter, we will discuss whether assembly of the various ABC transporter subunits occurs with high fidelity within the crowded cellular environment and whether promiscuity in assembly of transmembrane and cytoplasmic components can occur. We also discuss the new AlphaFold protein structure prediction tool which predicts a new type of transmembrane domain fold within the ABC transporters that is associated with cation exporters of bacteria and plants.
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Affiliation(s)
- Iqra Younus
- Faculty of Biology, Medicine and Health, School of Biological Sciences, The University of Manchester, Manchester, UK
| | - Sofia Kochkina
- Faculty of Biology, Medicine and Health, School of Biological Sciences, The University of Manchester, Manchester, UK
| | - Cheri C Choi
- Faculty of Biology, Medicine and Health, School of Biological Sciences, The University of Manchester, Manchester, UK
| | - Wenjuan Sun
- Faculty of Biology, Medicine and Health, School of Biological Sciences, The University of Manchester, Manchester, UK
| | - Robert C Ford
- Faculty of Biology, Medicine and Health, School of Biological Sciences, The University of Manchester, Manchester, UK.
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Chiku K, Yoshida M, Ono H, Kitaoka M. Generation of 3-deoxypentulose by the isomerization and β-elimination of 4-O-substituted glucose and fructose. Carbohydr Res 2021; 508:108402. [PMID: 34303026 DOI: 10.1016/j.carres.2021.108402] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 07/15/2021] [Accepted: 07/16/2021] [Indexed: 11/18/2022]
Abstract
Aldose-ketose isomerization is commonly used to prepare rare oligosaccharides such as maltulose (4-O-α-d-glucopyranosyl-d-fructose) and lactulose (4-O-β-d-galactopyranosyl-d-fructose). However, both sugars are degraded under alkaline conditions via β-elimination, while their subsequent benzylic acid rearrangement leads to the formation of isosaccharinic acids. Here, we investigated the behavior of maltose and maltulose upon heating in phosphate buffer solution at pH 7.5. Maltose was initially isomerized into maltulose. Maltulose was degraded via β-elimination, followed by keto-enol tautomerization, which led to the formation of a 1,3-dicarbonyl intermediate bearing an aldehyde group at the C-1 position and a ketone group at the C-3 position. Subsequent hydrolysis of this intermediate afforded formic acid and 3-deoxy-d-glycero-pent-2-ulose (1) as the major products based on HPLC and NMR data. In contrast, the formation of isosaccharinic acid via benzylic acid rearrangement, not the 3-deoxypentulose, was reported under the strongly alkaline conditions (Knill and Kennedy, 2003). The heat treatment of 1→4 linked oligo- and polysaccharides possessing glucose or fructose residue at the reducing end under neutral pH conditions could be applied for the practical preparation of a 3-deoxypentulose.
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Affiliation(s)
- Kazuhiro Chiku
- Faculty of Applied Life Science, Nippon Veterinary and Life Science University, 1-7-1 Kyonancho, Musashino-shi, Tokyo, 180-8602, Japan.
| | - Mitsuru Yoshida
- Faculty of Applied Life Science, Nippon Veterinary and Life Science University, 1-7-1 Kyonancho, Musashino-shi, Tokyo, 180-8602, Japan
| | - Hiroshi Ono
- Advanced Analysis Center, National Agriculture and Food Research Organization, 2-1-12 Kannondai, Tsukuba, Ibaraki, 305-8642, Japan
| | - Motomitsu Kitaoka
- Faculty of Agriculture, Niigata University, Niigata, 950-2181, Japan
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Mabanglo MF, Huddleston JP, Mukherjee K, Taylor ZW, Raushel FM. Structure and Reaction Mechanism of YcjR, an Epimerase That Facilitates the Interconversion of d-Gulosides to d-Glucosides in Escherichia coli. Biochemistry 2020; 59:2069-2077. [PMID: 32437133 PMCID: PMC7509853 DOI: 10.1021/acs.biochem.0c00334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
YcjR from Escherichia coli K-12 MG1655 catalyzes the manganese-dependent reversible epimerization of 3-keto-α-d-gulosides to the corresponding 3-keto-α-d-glucosides as a part of a proposed catabolic pathway for the transformation of d-gulosides to d-glucosides. The three-dimensional structure of the manganese-bound enzyme was determined by X-ray crystallography. The divalent manganese ion is coordinated to the enzyme by ligation to Glu-146, Asp-179, His-205, and Glu-240. When either of the two active site glutamate residues is mutated to glutamine, the enzyme loses all catalytic activity for the epimerization of α-methyl-3-keto-d-glucoside at C4. However, the E240Q mutant can catalyze hydrogen-deuterium exchange of the proton at C4 of α-methyl-3-keto-d-glucoside in solvent D2O. The E146Q mutant does not catalyze this exchange reaction. These results indicate that YcjR catalyzes the isomerization of 3-keto-d-glucosides via proton abstraction at C4 by Glu-146 to form a cis-enediolate intermediate that is subsequently protonated on the opposite face by Glu-240 to generate the corresponding 3-keto-d-guloside. This conclusion is supported by docking of the cis-enediolate intermediate into the active site of YcjR based on the known binding orientation of d-fructose and d-psicose in the active site of d-psicose-3-epimerase.
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Affiliation(s)
- Mark F. Mabanglo
- Department of Chemistry, Texas A&M University, College Station, Texas, 77843, USA
| | | | - Keya Mukherjee
- Department of Biochemistry & Biophysics, Texas A&M University, College Station, Texas, 77843, USA
| | - Zane W. Taylor
- Department of Biochemistry & Biophysics, Texas A&M University, College Station, Texas, 77843, USA
| | - Frank M. Raushel
- Department of Biochemistry & Biophysics, Texas A&M University, College Station, Texas, 77843, USA
- Department of Chemistry, Texas A&M University, College Station, Texas, 77843, USA
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Huddleston JP, Raushel FM. Functional Characterization of Cj1427, a Unique Ping-Pong Dehydrogenase Responsible for the Oxidation of GDP-d- glycero-α-d- manno-heptose in Campylobacter jejuni. Biochemistry 2020; 59:1328-1337. [PMID: 32168448 PMCID: PMC7500870 DOI: 10.1021/acs.biochem.0c00097] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The capsular polysaccharides (CPS) of Campylobacter jejuni contain multiple heptose residues with variable stereochemical arrangements at C3-C6. The immediate precursor to all of these possible variations is currently believed to be GDP-d-glycero-α-d-manno-heptose. Oxidation of this substrate at C4 enables subsequent epimerization reactions at C3-C5 that can be coupled to the dehydration/reduction at C5/C6. However, the enzyme responsible for the critical oxidation of C4 from GDP-d-glycero-α-d-manno-heptose has remained elusive. The enzyme Cj1427 from C. jejuni NCTC 11168 was shown to catalyze the oxidation of GDP-d-glycero-α-d-manno-heptose to GDP-d-glycero-4-keto-α-d-lyxo-heptose in the presence of α-ketoglutarate using mass spectrometry and nuclear magnetic resonance spectroscopy. At pH 7.4, the apparent kcat is 0.6 s-1, with a value of kcat/Km of 1.0 × 104 M-1 s-1 for GDP-d-glycero-α-d-manno-heptose. α-Ketoglutarate is required to recycle the tightly bound NADH nucleotide in the active site of Cj1427, which does not dissociate from the enzyme during catalysis.
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Affiliation(s)
- Jamison P. Huddleston
- Department of Chemistry, Texas A&M University, College Station, Texas, 77843, United States
| | - Frank M. Raushel
- Department of Chemistry, Texas A&M University, College Station, Texas, 77843, United States
- Department of Biochemistry & Biophysics, Texas A&M University, College Station, Texas 77843, United States
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