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Yu M, Arai N, Ochiai T, Ohyama T. Expression and function of an S1-type nuclease in the digestive fluid of a sundew, Drosera adelae. ANNALS OF BOTANY 2023; 131:335-346. [PMID: 36546767 PMCID: PMC9992940 DOI: 10.1093/aob/mcac150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Accepted: 12/11/2022] [Indexed: 06/17/2023]
Abstract
BACKGROUND AND AIMS Carnivorous plants trap and digest insects and similar-sized animals. Many studies have examined enzymes in the digestive fluids of these plants and have gradually unveiled the origins and gene expression of these enzymes. However, only a few attempts have been made at characterization of nucleases. This study aimed to reveal gene expression and the structural, functional and evolutionary characteristics of an S1-type nuclease (DAN1) in the digestive fluid of an Australian sundew, Drosera adelae, whose trap organ shows unique gene expression and related epigenetic regulation. METHODS Organ-specificity in Dan1 expression was examined using glandular tentacles, laminas, roots and inflorescences, and real-time PCR. The methylation status of the Dan1 promoter in each organ was clarified by bisulphite sequencing. The structural characteristics of DAN1 were studied by a comparison of primary structures of S1-type nucleases of three carnivorous and seven non-carnivorous plants. DAN1 was prepared using a cell-free protein synthesis system. Requirements for metal ions, optimum pH and temperature, and substrate preference were examined using conventional methods. KEY RESULTS Dan1 is exclusively expressed in the glandular tentacles and its promoter is almost completely unmethylated in all organs. This is in contrast to the S-like RNase gene da-I of Dr. adelae, which shows similar organ-specific expression, but is controlled by a promoter that is specifically unmethylated in the glandular tentacles. Comparison of amino acid sequences of S1-type nucleases identifies seven and three positions where amino acid residues are conserved only among the carnivorous plants and only among the non-carnivorous plants, respectively. DAN1 prefers a substrate RNA over DNA in the presence of Zn2+, Mn2+ or Ca2+ at an optimum pH of 4.0. CONCLUSIONS Uptake of phosphates from prey is suggested to be the main function of DAN1, which is very different from the known functions of S1-type nucleases. Evolution has modified the structure and expression of Dan1 to specifically function in the digestive fluid.
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Affiliation(s)
- Meng Yu
- Major in Integrative Bioscience and Biomedical Engineering, Graduate School of Science and Engineering, Waseda University, 2-2 Wakamatsu-cho, Shinjuku-ku, Tokyo 162-8480, Japan
| | - Naoki Arai
- Faculty of Engineering, Kanagawa University, 3-27-1 Rokkakubashi, Kanagawa-ku, Yokohama-shi, Kanagawa 221-8686, Japan
| | - Tadahiro Ochiai
- Major in Integrative Bioscience and Biomedical Engineering, Graduate School of Science and Engineering, Waseda University, 2-2 Wakamatsu-cho, Shinjuku-ku, Tokyo 162-8480, Japan
| | - Takashi Ohyama
- Major in Integrative Bioscience and Biomedical Engineering, Graduate School of Science and Engineering, Waseda University, 2-2 Wakamatsu-cho, Shinjuku-ku, Tokyo 162-8480, Japan
- Department of Biology, Faculty of Education and Integrated Arts and Sciences, Waseda University, 2-2 Wakamatsu-cho, Shinjuku-ku, Tokyo 162-8480, Japan
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Discovery of antitumor effects of leczymes. Glycoconj J 2022; 39:157-165. [DOI: 10.1007/s10719-021-10033-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 11/18/2021] [Accepted: 12/08/2021] [Indexed: 12/26/2022]
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Podzimek T, Přerovská T, Šantrůček J, Kovaľ T, Dohnálek J, Matoušek J, Lipovová P. N-glycosylation of tomato nuclease TBN1 produced in N. benthamiana and its effect on the enzyme activity. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2018; 276:152-161. [PMID: 30348313 DOI: 10.1016/j.plantsci.2018.08.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Revised: 08/21/2018] [Accepted: 08/22/2018] [Indexed: 06/08/2023]
Abstract
A unique analysis of an enzyme activity versus structure modification of the tomato nuclease R-TBN1 is presented. R-TBN1, the non-specific nuclease belonging to the S1-P1 nuclease family, was recombinantly produced in N. benthamiana. The native structure is posttranslationally modified by N-glycosylation at three sites. In this work, it was found that this nuclease is modified by high-mannose type N-glycosylation with a certain degree of macro- and microheterogeneity. To monitor the role of N-glycosylation in its activity, hypo- and hyperglycosylated nuclease mutants, R-TBN1 digested by α-mannosidase, and R-TBN1 deglycosylated by PNGase F were prepared. Deglycosylated R-TBN1 and mutant N94D/N112D were virtually inactive. Compared to R-TBN1 wt, both N94D and N112D mutants showed about 60% and 10% of the activity, respectively, while the N186D, D36S, and D36S/E104 N mutants were equally or even more active than R-TBN1 wt. The partial demannosylation of R-TBN1 did not affect the nuclease activity; moreover, a little shift in substrate specificity was observed. The results show two facts: 1) which sites must be occupied by a glycan for the proper folding and stability and 2) how N. benthamiana glycosylates the foreign nuclease. At the same time, the modifications can be interesting in designing the nuclease activity or specificity through its glycosylation.
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Affiliation(s)
- Tomáš Podzimek
- University of Chemical Technology Prague, Technická 3, Prague 6, 166 28, Czech Republic.
| | - Tereza Přerovská
- University of Chemical Technology Prague, Technická 3, Prague 6, 166 28, Czech Republic
| | - Jiří Šantrůček
- University of Chemical Technology Prague, Technická 3, Prague 6, 166 28, Czech Republic
| | - Tomáš Kovaľ
- Institute of Biotechnology of the Czech Academy of Sciences, v. v. i., Biocev, Průmyslová 595, 252 50, Vestec, Czech Republic
| | - Jan Dohnálek
- Institute of Biotechnology of the Czech Academy of Sciences, v. v. i., Biocev, Průmyslová 595, 252 50, Vestec, Czech Republic
| | - Jaroslav Matoušek
- Biology Centre, ASCR v.v.i., Institute of Plant Molecular Biology, Branišovská 32, 370 05, České Budějovice, Czech Republic
| | - Petra Lipovová
- University of Chemical Technology Prague, Technická 3, Prague 6, 166 28, Czech Republic
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Koval T, Dohnálek J. Characteristics and application of S1–P1 nucleases in biotechnology and medicine. Biotechnol Adv 2018; 36:603-612. [DOI: 10.1016/j.biotechadv.2017.12.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 12/08/2017] [Accepted: 12/13/2017] [Indexed: 12/18/2022]
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Matoušek J, Siglová K, Jakše J, Radišek S, Brass JRJ, Tsushima T, Guček T, Duraisamy GS, Sano T, Steger G. Propagation and some physiological effects of Citrus bark cracking viroid and Apple fruit crinkle viroid in multiple infected hop (Humulus lupulus L.). JOURNAL OF PLANT PHYSIOLOGY 2017; 213:166-177. [PMID: 28395198 DOI: 10.1016/j.jplph.2017.02.014] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Revised: 02/28/2017] [Accepted: 02/28/2017] [Indexed: 06/07/2023]
Abstract
The hop metabolome important for the brewing industry and for medical purposes is endangered worldwide due to multiple viroid infections affecting hop physiology. Combinatorial biolistic hop inoculation with Citrus bark cracking viroid (CBCVd), Apple fruit crinkle viroid (AFCVd), Hop latent viroid, and Hop stunt viroid (HSVd) showed a low CBCVd compatibility with HSVd, while all other viroid combinations were highly compatible. Unlike to other viroids, single CBCVd propagation showed a significant excess of (-) over (+) strands in hop, tomato, and Nicotiana benthamiana, but not in citruses. Inoculation of hop with all viroids led to multiple infections with unstable viroid levels in individual plants in the pre- and post-dormancy periods, and to high plant mortality and morphological disorders. Hop isolates of CBCVd and AFCVd were highly stable, only minor quasispecies were detected. CBCVd caused a strong suppression of some crucial mRNAs related to the hop prenylflavonoid biosynthesis pathway, while AFCVd-caused effects were moderate. According to mRNA degradome analysis, this suppression was not caused by a direct viroid-specific small RNA-mediated degradation. CBCVd infection led to a strong induction of two hop transcription factors from WRKY family and to a disbalance of WRKY/WDR1 complexes important for activation of lupulin genes.
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Affiliation(s)
- J Matoušek
- Biology Centre ASCR v.v.i, Institute of Plant Molecular Biology, Branišovská 31, České Budějovice 370 05, Czech Republic
| | - K Siglová
- Biology Centre ASCR v.v.i, Institute of Plant Molecular Biology, Branišovská 31, České Budějovice 370 05, Czech Republic; University of South Bohemia, Faculty of Science, Branišovská 31, 370 05 České Budějovice, Czech Republic
| | - J Jakše
- University of Ljubljana, Biotechnical Faculty, Department of Agronomy, Jamnikarjeva 101, SI-1000 Ljubljana, Slovenia
| | - S Radišek
- Slovenian Institute of Hop Research and Brewing, Cesta Žalskega tabora 2, SI-3310 Žalec, Slovenia
| | - Joseph R J Brass
- Institute of Physical Biology, Heinrich-Heine-Universität Düsseldorf, D-40204 Düsseldorf, Germany
| | - T Tsushima
- Faculty of Agriculture and Life Science, Hirosaki University, Bubkyo-cho, Hirosaki 036-8561, Japan
| | - T Guček
- Slovenian Institute of Hop Research and Brewing, Cesta Žalskega tabora 2, SI-3310 Žalec, Slovenia
| | - G S Duraisamy
- Biology Centre ASCR v.v.i, Institute of Plant Molecular Biology, Branišovská 31, České Budějovice 370 05, Czech Republic
| | - T Sano
- Faculty of Agriculture and Life Science, Hirosaki University, Bubkyo-cho, Hirosaki 036-8561, Japan
| | - G Steger
- Institute of Physical Biology, Heinrich-Heine-Universität Düsseldorf, D-40204 Düsseldorf, Germany.
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Structural and Catalytic Properties of S1 Nuclease from Aspergillus oryzae Responsible for Substrate Recognition, Cleavage, Non-Specificity, and Inhibition. PLoS One 2016; 11:e0168832. [PMID: 28036383 PMCID: PMC5201275 DOI: 10.1371/journal.pone.0168832] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Accepted: 12/07/2016] [Indexed: 01/08/2023] Open
Abstract
The single-strand-specific S1 nuclease from Aspergillus oryzae is an archetypal enzyme of the S1-P1 family of nucleases with a widespread use for biochemical analyses of nucleic acids. We present the first X-ray structure of this nuclease along with a thorough analysis of the reaction and inhibition mechanisms and of its properties responsible for identification and binding of ligands. Seven structures of S1 nuclease, six of which are complexes with products and inhibitors, and characterization of catalytic properties of a wild type and mutants reveal unknown attributes of the S1-P1 family. The active site can bind phosphate, nucleosides, and nucleotides in several distinguished ways. The nucleoside binding site accepts bases in two binding modes-shallow and deep. It can also undergo remodeling and so adapt to different ligands. The amino acid residue Asp65 is critical for activity while Asn154 secures interaction with the sugar moiety, and Lys68 is involved in interactions with the phosphate and sugar moieties of ligands. An additional nucleobase binding site was identified on the surface, which explains the absence of the Tyr site known from P1 nuclease. For the first time ternary complexes with ligands enable modeling of ssDNA binding in the active site cleft. Interpretation of the results in the context of the whole S1-P1 nuclease family significantly broadens our knowledge regarding ligand interaction modes and the strategies of adjustment of the enzyme surface and binding sites to achieve particular specificity.
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Stránský J, Koval’ T, Podzimek T, Týcová A, Lipovová P, Matoušek J, Kolenko P, Fejfarová K, Dušková J, Skálová T, Hašek J, Dohnálek J. Phosphate binding in the active centre of tomato multifunctional nuclease TBN1 and analysis of superhelix formation by the enzyme. Acta Crystallogr F Struct Biol Commun 2015; 71:1408-15. [PMID: 26527269 PMCID: PMC4631591 DOI: 10.1107/s2053230x15018324] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Accepted: 09/30/2015] [Indexed: 11/10/2022] Open
Abstract
Tomato multifunctional nuclease TBN1 belongs to the type I nuclease family, which plays an important role in apoptotic processes and cell senescence in plants. The newly solved structure of the N211D mutant is reported. Although the main crystal-packing motif (the formation of superhelices) is conserved, the details differ among the known structures. A phosphate ion was localized in the active site of the enzyme. The binding of the surface loop to the active centre is stabilized by the phosphate ion, which correlates with the observed aggregation of TBN1 in phosphate buffer. The conserved binding of the surface loop to the active centre suggests biological relevance of the contact in a regulatory function or in the formation of oligomers.
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Affiliation(s)
- Jan Stránský
- Institute of Biotechnology CAS, v.v.i., Vídeňská 1083, 142 20 Praha 4, Czech Republic
- Faculty of Nuclear Sciences and Physical Engineering, Czech Technical University, Břehová 7, 115 19 Praha 1, Czech Republic
| | - Tomáš Koval’
- Institute of Biotechnology CAS, v.v.i., Vídeňská 1083, 142 20 Praha 4, Czech Republic
- Institute of Macromolecular Chemistry CAS, v.v.i., Heyrovského nám. 2, 162 06 Praha 6, Czech Republic
| | - Tomáš Podzimek
- University of Chemistry and Technology, Technická 5, 166 28 Praha 6, Czech Republic
| | - Anna Týcová
- Institute of Plant Molecular Biology, Biology Centre, CAS, v.v.i., Branišovská 31, 370 05 České Budějovice, Czech Republic
- Faculty of Science, University of South Bohemia in České Budějovice, Branišovská 1760, 370 05 České Budějovice, Czech Republic
| | - Petra Lipovová
- University of Chemistry and Technology, Technická 5, 166 28 Praha 6, Czech Republic
| | - Jaroslav Matoušek
- Institute of Plant Molecular Biology, Biology Centre, CAS, v.v.i., Branišovská 31, 370 05 České Budějovice, Czech Republic
| | - Petr Kolenko
- Institute of Biotechnology CAS, v.v.i., Vídeňská 1083, 142 20 Praha 4, Czech Republic
- Faculty of Nuclear Sciences and Physical Engineering, Czech Technical University, Břehová 7, 115 19 Praha 1, Czech Republic
- Institute of Macromolecular Chemistry CAS, v.v.i., Heyrovského nám. 2, 162 06 Praha 6, Czech Republic
| | - Karla Fejfarová
- Institute of Biotechnology CAS, v.v.i., Vídeňská 1083, 142 20 Praha 4, Czech Republic
- Institute of Macromolecular Chemistry CAS, v.v.i., Heyrovského nám. 2, 162 06 Praha 6, Czech Republic
| | - Jarmila Dušková
- Institute of Biotechnology CAS, v.v.i., Vídeňská 1083, 142 20 Praha 4, Czech Republic
| | - Tereza Skálová
- Institute of Biotechnology CAS, v.v.i., Vídeňská 1083, 142 20 Praha 4, Czech Republic
| | - Jindřich Hašek
- Institute of Biotechnology CAS, v.v.i., Vídeňská 1083, 142 20 Praha 4, Czech Republic
| | - Jan Dohnálek
- Institute of Biotechnology CAS, v.v.i., Vídeňská 1083, 142 20 Praha 4, Czech Republic
- Institute of Macromolecular Chemistry CAS, v.v.i., Heyrovského nám. 2, 162 06 Praha 6, Czech Republic
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Rutkoski TJ, Kink JA, Strong LE, Raines RT. Human ribonuclease with a pendant poly(ethylene glycol) inhibits tumor growth in mice. Transl Oncol 2013; 6:392-7. [PMID: 23908681 PMCID: PMC3730013 DOI: 10.1593/tlo.13253] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2013] [Revised: 03/27/2013] [Accepted: 04/03/2013] [Indexed: 01/18/2023] Open
Abstract
Human pancreatic ribonuclease (RNase 1) is a small secretory protein that catalyzes the cleavage of RNA. This highly cationic enzyme can enter human cells spontaneously but is removed rapidly from circulation by glomerular filtration. Here, this shortcoming is addressed by attaching a poly(ethylene glycol) (PEG) moiety to RNase 1. The pendant has no effect on ribonucleolytic activity but does increase persistence in circulation. The RNase 1-PEG conjugates inhibit the growth of tumors in a xenograft mouse model of human lung cancer. Both retention in circulation and tumor growth inhibition correlate with the size of the pendant PEG. A weekly dose of the 60-kDa conjugate at 1 µmol/kg inhibited nearly all tumor growth without affecting body weight. Its molecular efficacy is ∼5000-fold greater than that of erlotinib, which is a small molecule in clinical use for the treatment of lung cancer. These data demonstrate that the addition of a PEG moiety can enhance the in vivo efficacy of human proteins that act within cells and highlight a simple means of converting an endogenous human enzyme into a cytotoxin with potential clinical utility.
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Affiliation(s)
- Thomas J Rutkoski
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI
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Koval' T, Lipovová P, Podzimek T, Matoušek J, Dušková J, Skálová T, Stěpánková A, Hašek J, Dohnálek J. Plant multifunctional nuclease TBN1 with unexpected phospholipase activity: structural study and reaction-mechanism analysis. ACTA CRYSTALLOGRAPHICA SECTION D: BIOLOGICAL CRYSTALLOGRAPHY 2013; 69:213-26. [PMID: 23385457 DOI: 10.1107/s0907444912043697] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2012] [Accepted: 10/22/2012] [Indexed: 11/11/2022]
Abstract
Type I plant nucleases play an important role in apoptotic processes and cell senescence. Recently, they have also been indicated to be potent anticancer agents in in vivo studies. The first structure of tomato nuclease I (TBN1) has been determined, its oligomerization and activity profiles have been analyzed and its unexpected activity towards phospholipids has been discovered, and conclusions are drawn regarding its catalytic mechanism. The structure-solution process required X-ray diffraction data from two crystal forms. The first form was used for phase determination; the second form was used for model building and refinement. TBN1 is mainly α-helical and is stabilized by four disulfide bridges. Three observed oligosaccharides are crucial for its stability and solubility. The active site is localized at the bottom of the positively charged groove and contains a zinc cluster that is essential for enzymatic activity. An equilibrium between monomers, dimers and higher oligomers of TBN1 was observed in solution. Principles of the reaction mechanism of the phosphodiesterase activity are suggested, with central roles for the zinc cluster, the nucleobase-binding pocket (Phe-site) and Asp70, Arg73 and Asn167. Based on the distribution of surface residues, possible binding sites for dsDNA and other nucleic acids with secondary structure were identified. The phospholipase activity of TBN1, which is reported for the first time for a nuclease, significantly broadens the substrate promiscuity of the enzyme, and the resulting release of diacylglycerol, which is an important second messenger, can be related to the role of TBN1 in apoptosis.
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Affiliation(s)
- Tomáš Koval'
- Institute of Macromolecular Chemistry, AS CR, v.v.i., Heyrovskeho nam. 2, 162 06 Praha 6, Czech Republic.
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Podzimek T, Matoušek J, Lipovová P, Poučková P, Spiwok V, Santrůček J. Biochemical properties of three plant nucleases with anticancer potential. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2011; 180:343-51. [PMID: 21421379 DOI: 10.1016/j.plantsci.2010.10.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2010] [Revised: 09/15/2010] [Accepted: 10/08/2010] [Indexed: 05/30/2023]
Abstract
Biochemical and structural properties of three recombinant (R), highly homologous, plant bifunctional nucleases from tomato (R-TBN1), hop (R-HBN1) and Arabis brassica (R-ABN1) were determined. These nucleases cleave single- and double-stranded substrates, as well as both RNA and DNA with nearly the same efficiency. In addition, they are able to cleave several artificial substrates and highly stable viroid RNA. They also possess 3'-nucleotidase activity; therefore, they can be classified as nuclease I family members. Interestingly, poly(G) is resistant to cleavage and moreover it inhibits dsDNase, ssDNase and RNase activity of the studied nucleases. All three nucleases exhibit zinc-dependence and a strong stimulatory effect of Zn²+ for dsDNA cleavage. 3-D models, predicted on the basis of experimental structure of P1 nuclease, show nine amino acid residues responsible for interactions with zinc atoms, located in the same positions as in P1 nuclease. It was also shown that R-TBN1, R-HBN1, and R-ABN1 are all N-glycosylated. Oligosaccharidic chains constitute about 16% of their MW. In addition, an anticancer potential of the R-ABN1 is compared in this work with previously tested R-TBN1, and R-HBN1. R-ABN1 injected intravenously showed 70% inhibitory effect on growth of human prostate carcinoma in athymic mice.
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Affiliation(s)
- Tomáš Podzimek
- Institute of Chemical Technology Prague, Technická 3, 166 28 Prague, Czech Republic; Biology Centre, ASCR v.v.i., Institute of Plant Molecular Biology, Branišovská 32, 37005 České Budějovice, Czech Republic.
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Koval' T, Lipovová P, Podzimek T, Matoušek J, Dušková J, Skálová T, Stěpánková A, Hašek J, Dohnálek J. Crystallization of recombinant bifunctional nuclease TBN1 from tomato. Acta Crystallogr Sect F Struct Biol Cryst Commun 2011; 67:124-8. [PMID: 21206042 PMCID: PMC3079990 DOI: 10.1107/s1744309110048177] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2010] [Accepted: 11/18/2010] [Indexed: 11/10/2022]
Abstract
The endonuclease TBN1 from Solanum lycopersicum (tomato) was expressed in Nicotiana benthamiana leaves and purified with suitable quality and in suitable quantities for crystallization experiments. Two crystal forms (orthorhombic and rhombohedral) were obtained and X-ray diffraction experiments were performed. The presence of natively bound Zn2+ ions was confirmed by X-ray fluorescence and by an absorption-edge scan. X-ray diffraction data were collected from the orthorhombic (resolution of 5.2 Å) and rhombohedral (best resolution of 3.2 Å) crystal forms. SAD, MAD and MR methods were applied for solution of the phase problem, with partial success. TBN1 contains three Zn2+ ions in a similar spatial arrangement to that observed in nuclease P1 from Penicillium citrinum.
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Affiliation(s)
- Tomáš Koval'
- Institute of Physics AS CR, v.v.i., Na Slovance 2, 182 21 Praha 8, Czech Republic.
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Fang EF, Ng TB. Ribonucleases of different origins with a wide spectrum of medicinal applications. Biochim Biophys Acta Rev Cancer 2010; 1815:65-74. [PMID: 20843477 DOI: 10.1016/j.bbcan.2010.09.001] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2010] [Revised: 09/03/2010] [Accepted: 09/03/2010] [Indexed: 12/18/2022]
Abstract
Ribonucleases (RNases) are a type of nucleases that catalyze the degradation of RNA into smaller components. They exist in a wide range of life forms from prokaryotes to eukaryotes. RNase-controlled RNA degradation is a determining factor in the control of gene expression, maturation and turnover, which are further associated with the progression of cancers and infectious diseases. Over the years, RNases purified from multiple origins have drawn increasing attention from medical scientists due to their remarkable antitumor properties. In this review, we present a brief summary of the representative RNases of fungal, bacterial, plant, and animal origins and outline their potential medicinal value in the treatment of tumor and AIDS. Among them, the most clinically promising RNases are mushroom RNases, Binase and Barnase from bacteria, ginseng RNases, and Onconase from frog (Rana pipiens). Fast developing protein engineering of RNases, which display more potent cytotoxic activity on and greater selectivity for malignant cells, has also aroused the interest of researchers. The multiple anti-cancer mechanisms of RNases are also included. To sum up, these inspiring studies unveil a new perspective for RNases as potential therapeutic agents.
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Affiliation(s)
- Evandro Fei Fang
- School of Biomedical Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong
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