1
|
Walter P, Mechaly A, Bous J, Haouz A, England P, Lai‐Kee‐Him J, Ancelin A, Hoos S, Baron B, Trapani S, Bron P, Labesse G, Munier‐Lehmann H. Structural basis for the allosteric inhibition of UMP kinase from Gram‐positive bacteria, a promising antibacterial target. FEBS J 2022; 289:4869-4887. [DOI: 10.1111/febs.16393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 01/18/2022] [Accepted: 02/09/2022] [Indexed: 11/28/2022]
Affiliation(s)
- Patrick Walter
- Unité de Chimie et Biocatalyse Département de Biologie Structurale et Chimie Institut Pasteur CNRS UMR3523 Paris France
| | - Ariel Mechaly
- Plate‐Forme de Cristallographie C2RT Institut Pasteur CNRS UMR3528 Paris France
| | - Julien Bous
- Centre de Biologie Structurale (CBS) Univ Montpellier INSERM CNRS Montpellier France
| | - Ahmed Haouz
- Plate‐Forme de Cristallographie C2RT Institut Pasteur CNRS UMR3528 Paris France
| | - Patrick England
- Plate‐Forme de Biophysique Moléculaire C2RT Institut Pasteur CNRS UMR3528 Paris France
| | - Joséphine Lai‐Kee‐Him
- Centre de Biologie Structurale (CBS) Univ Montpellier INSERM CNRS Montpellier France
| | - Aurélie Ancelin
- Centre de Biologie Structurale (CBS) Univ Montpellier INSERM CNRS Montpellier France
| | - Sylviane Hoos
- Plate‐Forme de Biophysique Moléculaire C2RT Institut Pasteur CNRS UMR3528 Paris France
| | - Bruno Baron
- Plate‐Forme de Biophysique Moléculaire C2RT Institut Pasteur CNRS UMR3528 Paris France
| | - Stefano Trapani
- Centre de Biologie Structurale (CBS) Univ Montpellier INSERM CNRS Montpellier France
| | - Patrick Bron
- Centre de Biologie Structurale (CBS) Univ Montpellier INSERM CNRS Montpellier France
| | - Gilles Labesse
- Centre de Biologie Structurale (CBS) Univ Montpellier INSERM CNRS Montpellier France
| | - Hélène Munier‐Lehmann
- Unité de Chimie et Biocatalyse Département de Biologie Structurale et Chimie Institut Pasteur CNRS UMR3523 Paris France
| |
Collapse
|
2
|
Abstract
We review literature on the metabolism of ribo- and deoxyribonucleotides, nucleosides, and nucleobases in Escherichia coli and Salmonella,including biosynthesis, degradation, interconversion, and transport. Emphasis is placed on enzymology and regulation of the pathways, at both the level of gene expression and the control of enzyme activity. The paper begins with an overview of the reactions that form and break the N-glycosyl bond, which binds the nucleobase to the ribosyl moiety in nucleotides and nucleosides, and the enzymes involved in the interconversion of the different phosphorylated states of the nucleotides. Next, the de novo pathways for purine and pyrimidine nucleotide biosynthesis are discussed in detail.Finally, the conversion of nucleosides and nucleobases to nucleotides, i.e.,the salvage reactions, are described. The formation of deoxyribonucleotides is discussed, with emphasis on ribonucleotidereductase and pathways involved in fomation of dUMP. At the end, we discuss transport systems for nucleosides and nucleobases and also pathways for breakdown of the nucleobases.
Collapse
|
3
|
Huang T, Yu X, Gelbič I, Guan X. RAP-PCR fingerprinting reveals time-dependent expression of development-related genes following differentiation process of Bacillus thuringiensis. Can J Microbiol 2015; 61:683-90. [DOI: 10.1139/cjm-2015-0212] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Gene expression profiles are important data to reveal the functions of genes putatively involved in crucial biological processes. RNA arbitrarily primed polymerase chain reaction (RAP-PCR) and specifically primed reverse transcription polymerase chain reaction (RT-PCR) were combined to screen differentially expressed genes following development of a commercial Bacillus thuringiensis subsp. kurstaki strain 8010 (serotype 3a3b). Six differentially expressed transcripts (RAP1 to RAP6) were obtained. RAP1 encoded a putative triple helix repeat-containing collagen or an exosporium protein H related to spore pathogenicity. RAP2 was homologous to a ClpX protease and an ATP-dependent protease La (LonB), which likely acted as virulence factors. RAP3 was homologous to a beta subunit of propionyl-CoA carboxylase required for the development of Myxococcus xanthus. RAP4 had homology to a quinone oxidoreductase involved in electron transport and ATP formation. RAP5 showed significant homology to a uridine kinase that mediates phosphorylation of uridine and azauridine. RAP6 shared high sequence identity with 3-methyl-2-oxobutanoate-hydroxymethyltransferase (also known as ketopantoate hydroxymethyltransferase or PanB) involved in the operation of the tricarboxylic acid cycle. The findings described here would help to elucidate the molecular mechanisms underlying the differentiation process of B. thuringiensis and unravel novel pathogenic genes.
Collapse
Affiliation(s)
- Tianpei Huang
- Key Laboratory of Biopesticide and Chemical Biology, Ministry of Education, Fujian Agriculture and Forestry University, 350002 Fuzhou, Fujian, People’s Republic of China
- Fujian–Taiwan Joint Center for Ecological Control of Crop Pests, 350002 Fuzhou, Fujian, People’s Republic of China
| | - Xiaomin Yu
- Key Laboratory of Biopesticide and Chemical Biology, Ministry of Education, Fujian Agriculture and Forestry University, 350002 Fuzhou, Fujian, People’s Republic of China
| | - Ivan Gelbič
- Biological Centre of the Czech Academy of Sciences, Institute of Entomology, Branišovská 31, 370 05 České Budějovice, Czech Republic
| | - Xiong Guan
- Key Laboratory of Biopesticide and Chemical Biology, Ministry of Education, Fujian Agriculture and Forestry University, 350002 Fuzhou, Fujian, People’s Republic of China
- Fujian–Taiwan Joint Center for Ecological Control of Crop Pests, 350002 Fuzhou, Fujian, People’s Republic of China
| |
Collapse
|
4
|
Lu S, Huang W, Wang Q, Shen Q, Li S, Nussinov R, Zhang J. The structural basis of ATP as an allosteric modulator. PLoS Comput Biol 2014; 10:e1003831. [PMID: 25211773 PMCID: PMC4161293 DOI: 10.1371/journal.pcbi.1003831] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2014] [Accepted: 07/29/2014] [Indexed: 12/20/2022] Open
Abstract
Adenosine-5’-triphosphate (ATP) is generally regarded as a substrate for energy currency and protein modification. Recent findings uncovered the allosteric function of ATP in cellular signal transduction but little is understood about this critical behavior of ATP. Through extensive analysis of ATP in solution and proteins, we found that the free ATP can exist in the compact and extended conformations in solution, and the two different conformational characteristics may be responsible for ATP to exert distinct biological functions: ATP molecules adopt both compact and extended conformations in the allosteric binding sites but conserve extended conformations in the substrate binding sites. Nudged elastic band simulations unveiled the distinct dynamic processes of ATP binding to the corresponding allosteric and substrate binding sites of uridine monophosphate kinase, and suggested that in solution ATP preferentially binds to the substrate binding sites of proteins. When the ATP molecules occupy the allosteric binding sites, the allosteric trigger from ATP to fuel allosteric communication between allosteric and functional sites is stemmed mainly from the triphosphate part of ATP, with a small number from the adenine part of ATP. Taken together, our results provide overall understanding of ATP allosteric functions responsible for regulation in biological systems. The endogenous ATP can be regarded as a substrate and an allosteric modulator in cellular signal transduction. We analyzed the properties of allosteric and substrate ATP-binding sites and found that the allosteric ATP-binding sites are less conserved than the substrate ATP-binding sites. Allosteric ATP molecules adopt both compact and extended conformations in the allosteric binding sites, while substrate ATP molecules adopt extended conformations in the substrate binding sites. The two different conformational characteristics may be responsible for ATP to exert distinct biological functions in cell signaling. In addition, to our knowledge, this study illuminates the first comprehensive atomic level investigations of ATP access to the corresponding allosteric and substrate ATP-binding sites. Specially, both the adenine and triphosphate parts of ATP could be an allosteric trigger to propagate the signal from the allosteric to functional sites. The detailed mechanism presented in this study may apply to other enzymes in complex with allosteric or substrate ATP molecules, and provide important insights for the molecular basis of ATP acting as a substrate and an allosteric modulator in cell signaling.
Collapse
Affiliation(s)
- Shaoyong Lu
- Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai JiaoTong University, School of Medicine, Shanghai, China
| | - Wenkang Huang
- Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai JiaoTong University, School of Medicine, Shanghai, China
| | - Qi Wang
- Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai JiaoTong University, School of Medicine, Shanghai, China
| | - Qiancheng Shen
- Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai JiaoTong University, School of Medicine, Shanghai, China
| | - Shuai Li
- Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai JiaoTong University, School of Medicine, Shanghai, China
| | - Ruth Nussinov
- Cancer and Inflammation Program, Leidos Biomedical Research, Inc., Frederick National Laboratory, National Cancer Institute, Frederick, Maryland, United States of America
- Department of Human Genetics and Molecular Medicine, Sackler School of Medicine, Sackler Institute of Molecular Medicine, Tel Aviv University, Tel Aviv, Israel
- * E-mail: (RN); (JZ)
| | - Jian Zhang
- Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai JiaoTong University, School of Medicine, Shanghai, China
- Shanghai Key Laboratory of Tumor Microenvironment and Inflammation, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- * E-mail: (RN); (JZ)
| |
Collapse
|
5
|
Doig P, Gorseth E, Nash T, Patten A, Gao N, Blackett C. Screening-based discovery of the first novel ATP competitive inhibitors of the Staphylococcus aureus essential enzyme UMP kinase. Biochem Biophys Res Commun 2013; 437:162-7. [PMID: 23806686 DOI: 10.1016/j.bbrc.2013.06.060] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2013] [Accepted: 06/17/2013] [Indexed: 10/26/2022]
Abstract
UMP kinase (PyrH) is an essential enzyme found only in bacteria, making it ideal as a target for the discovery of antibacterials. To identify inhibitors of PyrH, an assay employing Staphylococcus aureus PyrH coupled to pyruvate kinase/lactate dehydrogenase was developed and was used to perform a high throughput screen. A validated aminopyrimidine series was identified from screening. Kinetic characterization of this aminopyrimidine indicated it was a competitive inhibitor of ATP. We have shown that HTS can be used to identify potential leads for this novel target, the first ATP competitive inhibitor of PyrH reported.
Collapse
Affiliation(s)
- Peter Doig
- Discovery Sciences, AstraZeneca R&D Boston, Waltham, MA 02451, United States.
| | | | | | | | | | | |
Collapse
|
6
|
Chu CH, Liu MH, Chen PC, Lin MH, Li YC, Hsiao CD, Sun YJ. Structures of Helicobacter pylori uridylate kinase: insight into release of the product UDP. ACTA CRYSTALLOGRAPHICA SECTION D: BIOLOGICAL CRYSTALLOGRAPHY 2012; 68:773-83. [PMID: 22751662 DOI: 10.1107/s0907444912011407] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2011] [Accepted: 03/15/2012] [Indexed: 11/10/2022]
Abstract
Uridylate kinase (UMPK; EC 2.7.4.22) transfers the γ-phosphate of ATP to UMP, forming UDP. It is allosterically regulated by GTP. Structures of Helicobacter pylori UMPK (HpUMPK) complexed with GTP (HpUMPK-GTP) and with UDP (HpUMPK-UDP) were determined at 1.8 and 2.5 Å resolution, respectively. As expected, HpUMPK-GTP forms a hexamer with six GTP molecules at its centre. Interactions between HpUMPK and GTP are made by the β3 strand of the sheet, loop β3α4 and the α4 helix. In HpUMPK-UDP, the hexameric symmetry typical of UMPKs is absent. Only four of the HpUMPK molecules bind UDP; the other two HpUMPK molecules are in the UDP-free state. The asymmetric hexamer of HpUMPK-UDP, which has an exposed dimer interface, may assist in UDP release. Furthermore, the flexibility of the α2 helix, which interacts with UDP, is found to increase when UDP is absent in HpUMPK-UDP. In HpUMPK-GTP, the α2 helix is too flexible to be observed. This suggests that GTP binding may affect the conformation of the α2 helix, thereby promoting UDP release.
Collapse
Affiliation(s)
- Chen-Hsi Chu
- Institute of Bioinformatics and Structural Biology, National Tsing Hua University, Hsinchu 300, Taiwan
| | | | | | | | | | | | | |
Collapse
|
7
|
Hari Prasad O, Nanda Kumar Y, Reddy OVS, Chaudhary A, Sarma PVGK. Cloning, Expression, Purification and Characterization of UMP Kinase from Staphylococcus aureus. Protein J 2012; 31:345-52. [DOI: 10.1007/s10930-012-9410-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
8
|
A new class of adenylate kinase in methanogens is related to uridylate kinase. Arch Microbiol 2011; 194:141-5. [PMID: 22002406 DOI: 10.1007/s00203-011-0759-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2011] [Revised: 09/14/2011] [Accepted: 09/27/2011] [Indexed: 01/25/2023]
Abstract
The protein derived from the Methanocaldococcus jannaschii MJ0458 gene is annotated as a δ-1-pyrroline 5-carboxylate synthetase and is predicted to be related to aspartokinase and uridylate kinase. Analysis of the predicted protein sequence indicated that it is a unique kinase with few similarities to either uridylate or adenylate kinase. Here, we report that the MJ0458 gene product is a second type of archaeal adenylate kinase, AdkB. This enzyme is different from the established archaeal-specific adenylate kinase in both sequence and predicted tertiary structure.
Collapse
|
9
|
Labesse G, Benkali K, Salard-Arnaud I, Gilles AM, Munier-Lehmann H. Structural and functional characterization of the Mycobacterium tuberculosis uridine monophosphate kinase: insights into the allosteric regulation. Nucleic Acids Res 2010; 39:3458-72. [PMID: 21149268 PMCID: PMC3082897 DOI: 10.1093/nar/gkq1250] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Nucleoside Monophosphate Kinases (NMPKs) family are key enzymes in nucleotide metabolism. Bacterial UMPKs depart from the main superfamily of NMPKs. Having no eukaryotic counterparts they represent attractive therapeutic targets. They are regulated by GTP and UTP, while showing different mechanisms in Gram(+), Gram(–) and archaeal bacteria. In this work, we have characterized the mycobacterial UMPK (UMPKmt) combining enzymatic and structural investigations with site-directed mutagenesis. UMPKmt exhibits cooperativity toward ATP and an allosteric regulation by GTP and UTP. The crystal structure of the complex of UMPKmt with GTP solved at 2.5 Å, was merely identical to the modelled apo-form, in agreement with SAXS experiments. Only a small stretch of residues was affected upon nucleotide binding, pointing out the role of macromolecular dynamics rather than major structural changes in the allosteric regulation of bacterial UMPKs. We further probe allosteric regulation by site-directed mutagenesis. In particular, a key residue involved in the allosteric regulation of this enzyme was identified.
Collapse
Affiliation(s)
- Gilles Labesse
- Atelier de Bio- et Chimie Informatique Structurale, CNRS, UMR5048, Centre de Biochimie Structurale, 29 rue de Navacelles, F-34090 Montpellier, France
| | | | | | | | | |
Collapse
|
10
|
Abstract
Bacillus anthracis, the etiological agent of anthrax, is a spore-forming, Gram-positive bacterium and a category A biothreat agent. Screening of a library of transposon-mutagenized B. anthracis spores identified a mutant displaying an altered phenotype that harbored a mutated gene encoding the purine biosynthetic enzyme PurH. PurH is a bifunctional protein that catalyzes the final steps in the biosynthesis of the purine IMP. We constructed and characterized defined purH mutants of the virulent B. anthracis Ames strain. The virulence of the purH mutants was assessed in guinea pigs, mice, and rabbits. The spores of the purH mutants were as virulent as wild-type spores in mouse intranasal and rabbit subcutaneous infection models but were partially attenuated in a mouse intraperitoneal model. In contrast, the purH mutant spores were highly attenuated in guinea pigs regardless of the administration route. The reduced virulence in guinea pigs was not due solely to a germination defect, since both bacilli and toxins were detected in vivo, suggesting that the significant attenuation was associated with a growth defect in vivo. We hypothesize that an intact purine biosynthetic pathway is required for the virulence of B. anthracis in guinea pigs.
Collapse
|
11
|
Rostirolla DC, Breda A, Rosado LA, Palma MS, Basso LA, Santos DS. UMP kinase from Mycobacterium tuberculosis: Mode of action and allosteric interactions, and their likely role in pyrimidine metabolism regulation. Arch Biochem Biophys 2010; 505:202-12. [PMID: 21035424 DOI: 10.1016/j.abb.2010.10.019] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2010] [Revised: 10/21/2010] [Accepted: 10/21/2010] [Indexed: 11/28/2022]
Abstract
The pyrH-encoded uridine 5'-monophosphate kinase (UMPK) is involved in both de novo and salvage synthesis of DNA and RNA precursors. Here we describe Mycobacterium tuberculosis UMPK (MtUMPK) cloning and expression in Escherichia coli. N-terminal amino acid sequencing and electrospray ionization mass spectrometry analyses confirmed the identity of homogeneous MtUMPK. MtUMPK catalyzed the phosphorylation of UMP to UDP, using ATP-Mg²(+) as phosphate donor. Size exclusion chromatography showed that the protein is a homotetramer. Kinetic studies revealed that MtUMPK exhibits cooperative kinetics towards ATP and undergoes allosteric regulation. GTP and UTP are, respectively, positive and negative effectors, maintaining the balance of purine versus pyrimidine synthesis. Initial velocity studies and substrate(s) binding measured by isothermal titration calorimetry suggested that catalysis proceeds by a sequential ordered mechanism, in which ATP binds first followed by UMP binding, and release of products is random. As MtUMPK does not resemble its eukaryotic counterparts, specific inhibitors could be designed to be tested as antitubercular agents.
Collapse
Affiliation(s)
- Diana C Rostirolla
- Centro de Pesquisas em Biologia Molecular e Funcional, Instituto Nacional de Ciência e Tecnologia em Tuberculose, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | | | | | | | | | | |
Collapse
|
12
|
Marco-Marín C, Rubio V. The site for the allosteric activator GTP of Escherichia coli UMP kinase. FEBS Lett 2008; 583:185-9. [PMID: 19071117 DOI: 10.1016/j.febslet.2008.11.043] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2008] [Revised: 11/13/2008] [Accepted: 11/28/2008] [Indexed: 11/17/2022]
Abstract
UMP kinase (UMPK), a key bacterial pyrimidine nucleotide biosynthesis enzyme, is UTP-inhibited and GTP-activated. We delineate the GTP site of Escherichia coli UMPK by alanine mutagenesis of R92, H96, R103, W119 or R130, abolishing GTP activation; of S124 and R127, decreasing affinity for GTP; and of N111 and D115, with little detrimental effect. We exclude the correspondence with the modulatory ATP site of Bacillus anthracis UMPK, confirming the functionality of the GTP site found by Evrin. Mutants R92A, H96A and R127A are constitutively activated, suggesting key roles of these residues in allosteric signal transduction and of positive charge neutralization in triggering activation. No mutation hampered UTP inhibition, excluding overlapping of the UTP and GTP sites.
Collapse
Affiliation(s)
- Clara Marco-Marín
- Instituto de Biomedicina de Valencia (IBV-CSIC), Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER-ISCIII), Valencia, Spain
| | | |
Collapse
|
13
|
Tu JL, Chin KH, Wang AHJ, Chou SH. Unique GTP-binding pocket and allostery of uridylate kinase from a gram-negative phytopathogenic bacterium. J Mol Biol 2008; 385:1113-26. [PMID: 19059268 DOI: 10.1016/j.jmb.2008.11.030] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2008] [Revised: 11/03/2008] [Accepted: 11/12/2008] [Indexed: 11/29/2022]
Abstract
Using X-ray diffraction methodology, we have successfully determined the tertiary structures of the apo- and GTP-bound forms of uridylate kinase (UMPK) from the gram-negative plant pathogen Xanthomonas campestris with crystals grown under a strong magnetic field. The flexible ATP- and UMP-binding loops are clearly shown under this situation. X. campestris UMPK contains a unique patch of noticeably positive nature from residue R100 to residue R127, allowing it to form a special GTP-binding pocket in the central hole of the structure. Although GTP is found to be situated in a pocket similar to that of the ATP-binding pocket in Bacillus anthracis UMPK, superimposition between the two pockets indicates that they adopt very distinct conformations. Detailed structural analyses of X. campestris UMPK between its apo- and GTP-bound forms reveal that binding of GTP does not induce global conformational change for X. campestris UMPK and only moderates movements for the ATP- and UMP-binding loops. Binding of GTP effector seems to "heat up" X. campestris UMPK, causing overall increases of B-factors for the protein, except for residues interacting with the guanine base. Moderate increase of enzyme activity, as is the case detected in other gram-negative bacteria, is observed for X. campestris UMPK in the presence of an allosteric GTP effector. Given that the GTP molecules bind in the central cavity of the hexamer and that each GTP molecule interacts with more than one monomer, it is likely that binding of GTP modifies the hexameric assembly to exert long-range allosteric control on X. campestris UMPK, similar to that suggested for the effect of ATP effector on B. anthracis UMPK.
Collapse
Affiliation(s)
- Jhe-Le Tu
- Institute of Biochemistry, National Chung Hsing University, Taichung 40227, Taiwan, ROC
| | | | | | | |
Collapse
|