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Vande Voorde J, Vervaeke P, Liekens S, Balzarini J. Mycoplasma hyorhinis-encoded cytidine deaminase efficiently inactivates cytosine-based anticancer drugs. FEBS Open Bio 2015; 5:634-9. [PMID: 26322268 PMCID: PMC4541722 DOI: 10.1016/j.fob.2015.07.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Revised: 07/24/2015] [Accepted: 07/30/2015] [Indexed: 11/25/2022] Open
Abstract
Mycoplasmas may colonize tumor tissue in patients. Mycoplasma-encoded cytidine deaminase deaminates cytosine-based anticancer drugs. The activity of gemcitabine is compromised in mycoplasma-infected tumor cells. Gemcitabine activity can be restored by nucleosides or a PNP inhibitor.
Mycoplasmas may colonize tumor tissue in patients. The cytostatic activity of gemcitabine was dramatically decreased in Mycoplasma hyorhinis-infected tumor cell cultures compared with non-infected tumor cell cultures. This mycoplasma-driven drug deamination could be prevented by exogenous administration of the cytidine deaminase (CDA) inhibitor tetrahydrouridine, but also by the natural nucleosides or by a purine nucleoside phosphorylase inhibitor. The M. hyorhinis-encoded CDAHyor gene was cloned, expressed as a recombinant protein and purified. CDAHyor was found to be more catalytically active than its human equivalent and efficiently deaminates (inactivates) cytosine-based anticancer drugs. CDAHyor expression at the tumor site may result in selective drug inactivation and suboptimal therapeutic efficiency.
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Key Words
- (d)Ado, (2′-deoxy)adenosine
- (d)Guo, (2′-deoxy)guanosine
- (d)Ino, (2′-deoxy)inosine
- (d)Urd, (2′-deoxy)uridine
- 3TC, 2′,3′-dideoxy-3′-thiacytidine
- CDA, cytidine deaminase
- Cancer
- Cytidine deaminase
- Gemcitabine
- Imm-H, Immucillin-H
- Mycoplasma
- NA, nucleoside analogue
- Nucleoside analogue
- PNP, purine nucleoside phosphorylase
- Purine nucleoside phosphorylase
- ara-Cyd, cytosine arabinoside
- dFdC, gemcitabine
- dFdU, 2′,2′-difluoro-2′-deoxyuridine
- dThd, thymidine
- ddC, 2′,3′-dideoxycytidine
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Affiliation(s)
| | | | | | - Jan Balzarini
- Corresponding author. Tel.: +32 16 337367; fax: +32 16 337340.
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Hitchcock DS, Fedorov AA, Fedorov EV, Almo SC, Raushel FM. Discovery of a bacterial 5-methylcytosine deaminase. Biochemistry 2014; 53:7426-35. [PMID: 25384249 PMCID: PMC4255641 DOI: 10.1021/bi5012767] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
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5-Methylcytosine
is found in all domains of life, but the bacterial
cytosine deaminase from Escherichia coli (CodA) will
not accept 5-methylcytosine as a substrate. Since significant amounts
of 5-methylcytosine are produced in both prokaryotes and eukaryotes,
this compound must eventually be catabolized and the fragments recycled
by enzymes that have yet to be identified. We therefore initiated
a comprehensive phylogenetic screen for enzymes that may be capable
of deaminating 5-methylcytosine to thymine. From a systematic analysis
of sequence homologues of CodA from thousands of bacterial species,
we identified putative cytosine deaminases where a “discriminating”
residue in the active site, corresponding to Asp-314 in CodA from E. coli, was no longer conserved. Representative examples
from Klebsiella pneumoniae (locus tag: Kpn00632), Rhodobacter sphaeroides (locus tag: Rsp0341), and Corynebacterium glutamicum (locus tag: NCgl0075) were demonstrated
to efficiently deaminate 5-methylcytosine to thymine with values of kcat/Km of 1.4 ×
105, 2.9 × 104, and 1.1 × 103 M–1 s–1, respectively. These
three enzymes also catalyze the deamination of 5-fluorocytosine to
5-fluorouracil with values of kcat/Km of 1.2 × 105, 6.8 × 104, and 2.0 × 102 M–1 s–1, respectively. The three-dimensional structure of
Kpn00632 was determined by X-ray diffraction methods with 5-methylcytosine
(PDB id: 4R85), 5-fluorocytosine (PDB id: 4R88), and phosphonocytosine (PDB id: 4R7W) bound in the active
site. When thymine auxotrophs of E. coli express
these enzymes, they are capable of growth in media lacking thymine
when supplemented with 5-methylcytosine. Expression of these enzymes
in E. coli is toxic in the presence of 5-fluorocytosine,
due to the efficient transformation to 5-fluorouracil.
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Affiliation(s)
- Daniel S Hitchcock
- Department of Biochemistry & Biophysics and ‡Department of Chemistry, Texas A&M University , College Station, Texas 77843, United States
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Costanzi S, Vincenzetti S, Cristalli G, Vita A. Human cytidine deaminase: A three-dimensional homology model of a tetrameric metallo-enzyme inferred from the crystal structure of a distantly related dimeric homologue. J Mol Graph Model 2006; 25:10-6. [PMID: 16303324 DOI: 10.1016/j.jmgm.2005.10.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2005] [Revised: 07/11/2005] [Accepted: 10/19/2005] [Indexed: 10/25/2022]
Abstract
Cytidine deaminase (CDA) is a cytosolic metalloprotein whose functional unit can be either a homotetramer (T-CDA) or a homodimer (D-CDA), depending on the species. In 1994, the first crystal structure of the dimeric Escherichia coli CDA has been published. However, a crystal structure of a tetrameric CDA was not determined until 2002. Prior to the disclosure of the experimentally elucidated structure of a tetrameric CDA, we derived a homology model of the human T-CDA employing the crystal structure of the dimeric E. coli CDA as a template. The comparison of our theoretical model with the crystal structure of the human T-CDA, subsequently published in 2004, validates our prediction: not only of the structural features of the monomer and the details of the binding site, but also the multimeric arrangement of the subunits were determined with high accuracy in our model. By means of a phylogenetic analysis conducted on CDAs from various organisms, we demonstrate that the E. coli CDA is one of the furthest known homologues of the human enzyme. Nonetheless, despite the evolutionary distance and, more importantly, the different multimeric arrangement of their functional units, the E. coli CDA proved to have all the necessary information to accurately infer the structure of its human homologue.
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Affiliation(s)
- Stefano Costanzi
- Computational Chemistry Core Laboratory, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 12A Center Drive Rm 4051 MSC 5646, Bethesda, MD 20892-0810, USA.
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Dance GS, Beemiller P, Yang Y, Mater DV, Mian IS, Smith HC. Identification of the yeast cytidine deaminase CDD1 as an orphan C-->U RNA editase. Nucleic Acids Res 2001; 29:1772-80. [PMID: 11292850 PMCID: PMC31303 DOI: 10.1093/nar/29.8.1772] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Yeast co-expressing rat APOBEC-1 and a fragment of human apolipoprotein B (apoB) mRNA assembled functional editosomes and deaminated C6666 to U in a mooring sequence-dependent fashion. The occurrence of APOBEC-1-complementing proteins suggested a naturally occurring mRNA editing mechanism in yeast. Previously, a hidden Markov model identified seven yeast genes encoding proteins possessing putative zinc-dependent deaminase motifs. Here, only CDD1, a cytidine deaminase, is shown to have the capacity to carry out C-->U editing on a reporter mRNA. This is only the second report of a cytidine deaminase that can use mRNA as a substrate. CDD1-dependent editing was growth phase regulated and demonstrated mooring sequence-dependent editing activity. Candidate yeast mRNA substrates were identified based on their homology with the mooring sequence-containing tripartite motif at the editing site of apoB mRNA and their ability to be edited by ectopically expressed APOBEC-1. Naturally occurring yeast mRNAs edited to a significant extent by CDD1 were, however, not detected. We propose that CDD1 be designated an orphan C-->U editase until its native RNA substrate, if any, can be identified and that it be added to the CDAR (cytidine deaminase acting on RNA) family of editing enzymes.
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Affiliation(s)
- G S Dance
- Department of Biochemistry and Biophysics, University of Rochester, 601 Elmwood Avenue, Rochester, NY 14642, USA
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Faivre-Nitschke SE, Grienenberger JM, Gualberto JM. A prokaryotic-type cytidine deaminase from Arabidopsis thaliana gene expression and functional characterization. EUROPEAN JOURNAL OF BIOCHEMISTRY 1999; 263:896-903. [PMID: 10469156 DOI: 10.1046/j.1432-1327.1999.00591.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The gene and cDNA of an Arabidopsis thaliana cytidine deaminase (CDA) were cloned and sequenced. The gene, At-cda1, is located on chromosome 2 and is expressed in all plant tissues tested, although with quantitative differences. Expression analysis suggest that At-cda1 probably codes for the housekeeping cytidine deaminase of Arabidopsis. The gene was functionally expressed in Escherichia coli and the protein, At-CDA1, shows similar enzymatic and substrate specificities as conventional cytidine deaminases: it deaminates cytidine and deoxycytidine and is competitively inhibited by cytosine-containing compounds. Because the protein shows no affinity to RNA, it is not likely to be involved in RNA-editing by C-to-U deamination. When compared to cytidine deaminases from other organisms, it becomes clear that At-CDA1 is related, both in sequence and structure, to the CDA of E. coli and other gram-negative bacteria. The eubacterial nature of the Arabidopsis CDA suggests that it is an additional example of a plant gene of endosymbiotic origin.
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Vincenzetti S, Cambi A, Neuhard J, Schnorr K, Grelloni M, Vita A. Cloning, expression, and purification of cytidine deaminase from Arabidopsis thaliana. Protein Expr Purif 1999; 15:8-15. [PMID: 10024464 DOI: 10.1006/prep.1998.0959] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The complementary DNA (cDNA) coding for Arabidopsis thaliana cytidine deaminase 1 (AT-CDA1) was obtained from the amplified A. thaliana cDNA expression library, provided by R. W. Davis (Stanford University, CA). AT-CDA1 cDNA was subcloned into the expression vector pTrc99-A and the protein, expressed in Escherichia coli following induction with isopropyl 1-thio-beta-d-galactopyranoside, showed high cytidine deaminase activity. The nucleotide sequence showed a 903-bp open reading frame encoding a polypeptide of 301 amino acids with a calculated molecular mass of 32,582. The deduced amino acid sequence of AT-CDA1 showed no transit peptide for targeting to the chloroplast or mitochondria indicating that this form of cytidine deaminase is probably expressed in the cytosol. The recombinant AT-CDA1 was purified to homogeneity by a heat treatment followed by an ion-exchange chromatography. The final enzyme preparation was >98% pure as judged by SDS-PAGE and showed a specific activity of 74 U/mg. The molecular mass of AT-CDA1 estimated by gel filtration was 63 kDa, indicating, in contrast to the other eukaryotic CDAs, that the enzyme is a dimer composed of two identical subunits. Inductively coupled plasma-optical emission spectroscopy analysis indicated that the enzyme contains 1 mol of zinc atom per mole of subunit. The kinetic properties of AT-CDA1 both toward the natural substrates and with analogs indicated that the catalytic mechanism of the plant enzyme is probably very similar to that of the human the E. coli enzymes.
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Affiliation(s)
- S Vincenzetti
- Dipartimento di Scienze Morfologiche e Biochimiche Comparate, Università di Camerino, Camerino (MC), Italy
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Cristalli G, Volpini R, Vittori S, Camaioni E, Rafaiani G, Potenza S, Vita A. Diazepinone Nucleosides as Inhibitors of Cytidine Deaminase. ACTA ACUST UNITED AC 1996. [DOI: 10.1080/07328319608002457] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Cacciamani T, Vita A, Cristalli G, Vincenzetti S, Natalini P, Ruggieri S, Amici A, Magni G. Purification of human cytidine deaminase: molecular and enzymatic characterization and inhibition by synthetic pyrimidine analogs. Arch Biochem Biophys 1991; 290:285-92. [PMID: 1929398 DOI: 10.1016/0003-9861(91)90543-r] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Cytidine deaminase has been purified to homogeneity from human placenta by a rapid and efficient procedure consisting of affinity chromatography followed by hydrophobic interaction chromatography. The final enzyme preparation showed a specific activity of 64.1 units/mg, corresponding to about 46,000-fold purification with respect to the crude extract. The enzyme is a 52-kDa oligomeric protein composed of four apparently identical subunits. The acidic isoelectric point is 4.5. The enzyme's stability is strictly dependent on the presence of reducing agents. Amino acid analysis reveals the presence of five thiol groups per monomer which cannot be titrated by Ellman's reagent in the native enzyme. However, the presence of sulfhydryl groups involved in the catalytic activity was evidenced by the inhibition exerted by p-chloromercuribenzoate and heavy metal ions. In addition, the protection effected by the substrate against the p-chloromercuribenzoate inhibition and the competitive inhibition exerted by 5-(chloromercuri)cytidine suggest the presence of a thiol group(s) in the catalytic site of the enzyme. pH studies have shown that the rapid decline of activity occurring at pH 4.5 might result from the protonation of the pyrimidine ring at the N-3 position. The enzyme catalyzes the deamination of cytidine, deoxycytidine, and several analogs, including antineoplastic agents, thus abolishing their pharmacological activity. Therefore, several pyrimidine nucleoside analogs have been tested as potential inhibitors of the enzyme. The competitive inhibition exerted by cytidine analogs having the ribose moiety replaced by aliphatic chains is interesting.
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Affiliation(s)
- T Cacciamani
- Dipartimento di Biologia M.C.A., Università di Camerino, Italy
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Vita A, Vincenzetti S, Amici A, Ferretti E, Magni G. Cytidine deaminase: a rapid method of purification and some properties of the enzyme from human placenta. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1991; 309B:235-8. [PMID: 1781374 DOI: 10.1007/978-1-4615-7703-4_52] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- A Vita
- Dipartimento di Biologia C.M.A., Università di Camerino, Italy
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Abstract
The pyrimidine antimetabolite drugs consist of base and nucleoside analogues of the naturally occurring pyrimidines uracil, thymine and cytosine. As is typical of antimetabolites, these drugs have a strong structural similarity to endogenous nucleic acid precursors. The structural differences are usually substitutions at one of the carbons in the pyrimidine ring itself or substitutions at on of the hydrogens attached to the ring of the pyrimidine or sugar (ribose or deoxyribose). Despite the differences noted above, these analogues, can still be taken up into cells and then metabolized via anabolic or catabolic pathways used by endogenous pyrimidines. Cytotoxicity results when the antimetabolite either is incorporated in place of the naturally occurring pyrimidine metabolite into a key molecule (such as RNA or DNA) or competes with the naturally occurring pyrimidine metabolite for a critical enzyme. There are four pyrimidine antimetabolites that are currently used extensively in clinical oncology. These include the fluoropyrimidines fluorouracil and fluorodeoxyuridine, and the cytosine analogues, cytosine arabinoside and azacytidine.
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Affiliation(s)
- G C Daher
- Department of Pharmacology, University of Alabama, Birmingham 35294
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Incomplete Factorial Search for Conditions Leading to High Quality Crystals of Escherichia coli Cytidine Deaminase Complexed to a Transition State Analog Inhibitor. J Biol Chem 1989. [DOI: 10.1016/s0021-9258(18)83491-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Vita A, Cacciamani T, Natalini P, Ruggieri S, Magni G. Cytidine deaminase from human spleen. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1989; 253B:71-7. [PMID: 2610147 DOI: 10.1007/978-1-4684-5676-9_12] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- A Vita
- Departimento di Biologia Cellulare, Universita di Camerino, Italy
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Traut TW. Enzymes of nucleotide metabolism: the significance of subunit size and polymer size for biological function and regulatory properties. CRC CRITICAL REVIEWS IN BIOCHEMISTRY 1988; 23:121-69. [PMID: 3048887 DOI: 10.3109/10409238809088318] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The 72 enzymes in nucleotide metabolism, from all sources, have a distribution of subunit sizes similar to those from other surveys: an average subunit Mr of 47,900, and a median size of 33,300. The same enzyme, from whatever source, usually has the same subunit size (there are exceptions); enzymes having a similar activity (e.g., kinases, deaminases) usually have a similar subunit size. Most simple enzymes in all EC classes (except class 6, ligases/synthetases) have subunit sizes of less than 30,000. Since structural domains defined in proteins tend to be in the Mr range of 5,000 to 30,000, it may be that most simple enzymes are formed as single domains. Multifunctional proteins and ligases have subunits generally much larger than Mr 40,000. Analyses of several well-characterized ligases suggest that they also have two or more distinct catalytic sites, and that ligases therefore are also multifunctional proteins, containing two or more domains. Cooperative kinetics and evidence for allosteric regulation are much more frequently associated with larger enzymes: such complex functions are associated with only 19% of enzymes having a subunit Mr less than or equal to 29,000, and with 86% of all enzymes having a subunit Mr greater than 50,000. In general, larger enzymes have more functions. Only 20% of these enzymes appear to be monomers; the rest are homopolymers and rarely are they heteropolymers. Evidence for the reversible dissociation of homopolymers has been found for 15% of the enzymes. Such changes in quaternary structure are usually mediated by appropriate physiological effectors, and this may serve as a mechanism for their regulation between active and less active forms. There is considerable structural organization of the various pathways: 19 enzymes are found in various multifunctional proteins, and 13 enzymes are found in different types of multienzyme complexes.
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Affiliation(s)
- T W Traut
- Department of Biochemistry, University of North Carolina School of Medicine, Chapel Hill
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