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Sanders KL, Catto LE, Bellamy SRW, Halford SE. Targeting individual subunits of the FokI restriction endonuclease to specific DNA strands. Nucleic Acids Res 2009; 37:2105-15. [PMID: 19223323 PMCID: PMC2673415 DOI: 10.1093/nar/gkp046] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Many restriction endonucleases are dimers that act symmetrically at palindromic DNA sequences, with each active site cutting one strand. In contrast, FokI acts asymmetrically at a non-palindromic sequence, cutting ‘top’ and ‘bottom’ strands 9 and 13 nucleotides downstream of the site. FokI is a monomeric protein with one active site and a single monomer covers the entire recognition sequence. To cut both strands, the monomer at the site recruits a second monomer from solution, but it is not yet known which DNA strand is cut by the monomer bound to the site and which by the recruited monomer. In this work, mutants of FokI were used to show that the monomer bound to the site made the distal cut in the bottom strand, whilst the recruited monomer made in parallel the proximal cut in the top strand. Procedures were also established to direct FokI activity, either preferentially to the bottom strand or exclusively to the top strand. The latter extends the range of enzymes for nicking specified strands at specific sequences, and may facilitate further applications of FokI in gene targeting.
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Affiliation(s)
- Kelly L Sanders
- Department of Biochemistry, School of Medical Sciences, University of Bristol, Bristol, UK
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2
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Meyer S, Temme C, Wahle E. Messenger RNA turnover in eukaryotes: pathways and enzymes. Crit Rev Biochem Mol Biol 2005; 39:197-216. [PMID: 15596551 DOI: 10.1080/10409230490513991] [Citation(s) in RCA: 243] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The control of mRNA degradation is an important component of the regulation of gene expression since the steady-state concentration of mRNA is determined both by the rates of synthesis and of decay. Two general pathways of mRNA decay have been described in eukaryotes. Both pathways share the exonucleolytic removal of the poly(A) tail (deadenylation) as the first step. In one pathway, deadenylation is followed by the hydrolysis of the cap and processive degradation of the mRNA body by a 5' exonuclease. In the second pathway, the mRNA body is degraded by a complex of 3' exonucleases before the remaining cap structure is hydrolyzed. This review discusses the proteins involved in the catalysis and control of both decay pathways.
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Affiliation(s)
- Sylke Meyer
- Institut für Biochemie, Martin-Luther-Universität Halle-Wittenberg, Halle, Germany
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3
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Körner CG, Wahle E. Poly(A) tail shortening by a mammalian poly(A)-specific 3'-exoribonuclease. J Biol Chem 1997; 272:10448-56. [PMID: 9099687 DOI: 10.1074/jbc.272.16.10448] [Citation(s) in RCA: 175] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
3'-Exonucleolytic removal of the poly(A) tail is the first and often rate-limiting step in the decay of many eucaryotic mRNAs. In a cytoplasmic extract from HeLa cells, the poly(A) tail of mRNA was degraded from the 3'-end. In agreement with earlier in vivo observations, prominent decay intermediates differed in length by about 30 nucleotides. The Mg2+-dependent, poly(A)-specific 3'-exoribonuclease responsible for this poly(A) shortening activity was purified from calf thymus. A polypeptide of 74 kDa copurified with the activity. The deadenylating nuclease (DAN) required a free 3'-OH group, released solely 5'-AMP, degraded RNA in a distributive fashion, and preferred poly(A) as a substrate. At low salt concentration, the activity of purified DAN was strongly dependent on spermidine or other, yet unidentified factors. Under these reaction conditions, DAN was also stimulated by the cytoplasmic poly(A)-binding protein I (PAB I). At physiological salt concentration, the stimulatory effect of spermidine was weak and PAB I was inhibitory. At either salt concentration DAN and PAB I reconstituted poly(A) shortening with the same pattern of intermediates seen in cytoplasmic extract. The properties of DAN suggest that the enzyme might be involved in the deadenylation of mRNA in vivo.
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Affiliation(s)
- C G Körner
- Institut für Biochemie, Justus-Liebig-Universität, Heinrich-Buff-Ring 58, D-35392 Giessen, Germany
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4
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Pfeiffer S, Karimi-Nejad Y, Rüterjans H. Limits of NMR structure determination using variable target function calculations: ribonuclease T1, a case study. J Mol Biol 1997; 266:400-23. [PMID: 9047372 DOI: 10.1006/jmbi.1996.0784] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Limits of NMR structure determination using multidimensional NMR spectroscopy, variable target function calculations and relaxation matrix analysis were explored using the model protein ribonuclease T1 (RNase T1). The enzyme consists of 104 amino acid residues and has a molecular mass of approximately 11 kDa. Primary experimental data comprise 1856 assigned NOE intensities, 493 3J coupling constants and 62 values of amid proton exchange rates. From these data, 2580 distance bounds, 168 allowed ranges for torsional angles and stereospecific assignments for 75% of beta-methylene protons as well as for 80% of diastereotopic methyl groups were derived. Whenever possible, the distance restraints were refined in a relaxation matrix analysis including amid proton exchange data for improvement of lower distance limits. Description of side-chain conformations were based on various models of motional averaging of 3J coupling constants. The final structure ensemble was selected from the starting ensemble comparing the global precision of structures with order parameters derived from 15N relaxation time measurements. Significant differences between the structure of RNase T1 in solution and in the crystal became apparent from a comparison of the two highly resolved structures.
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Affiliation(s)
- S Pfeiffer
- Institut für Biophysikalische Chemie, Johann Wolfgang Goethe-Universität, Biozentrum, Frankfurt, Germany
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5
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Wahle E, Kühn U. The mechanism of 3' cleavage and polyadenylation of eukaryotic pre-mRNA. PROGRESS IN NUCLEIC ACID RESEARCH AND MOLECULAR BIOLOGY 1997; 57:41-71. [PMID: 9175430 DOI: 10.1016/s0079-6603(08)60277-9] [Citation(s) in RCA: 73] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- E Wahle
- Institut für Biochemic, Justus-Liebig-Universität Giessen, Germany
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6
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Kolmes B, Franke I, Friedhoff P, Pingoud A. Analysis of the reaction mechanism of the non-specific endonuclease of Serratia marcescens using an artificial minimal substrate. FEBS Lett 1996; 397:343-6. [PMID: 8955376 DOI: 10.1016/s0014-5793(96)01210-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
We have studied the mechanism of action of the Serratia nuclease using deoxythymidine 3',5'-bis-(p-nitrophenyl-phosphate) as a substrate. A comparison of the activity with which the wild-type enzyme and several mutant enzymes attack this artificial substrate and herring sperm DNA, respectively, supports the suggestion that His89 is the general base and a Mg2+ ion bound to Glu127 the general acid in the mechanism of phosphodiester bond hydrolysis by the Serratia nuclease, and that Asn119 directly participates in catalysis, for example by transition state stabilisation. Arg57, Arg87 and Arg131, essential for nuclease activity, are not needed for cleavage of the artificial substrate, suggesting that they are involved in binding and positioning of nucleic acid substrates.
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Affiliation(s)
- B Kolmes
- Institut für Biochemie, Fachbereich Biologie, Justus-Liebig-Universität, Giessen, Germany
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7
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8
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Ponting CP, Kerr ID. A novel family of phospholipase D homologues that includes phospholipid synthases and putative endonucleases: identification of duplicated repeats and potential active site residues. Protein Sci 1996; 5:914-22. [PMID: 8732763 PMCID: PMC2143407 DOI: 10.1002/pro.5560050513] [Citation(s) in RCA: 274] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Phosphatidylcholine-specific phospholipase D (PLD) enzymes catalyze hydrolysis of phospholipid phosphodiester bonds, and also transphosphatidylation of phospholipids to acceptor alcohols. Bacterial and plant PLD enzymes have not been shown previously to be homologues or to be homologous to any other protein. Here we show, using sequence analysis methods, that bacterial and plant PLDs show significant sequence similarities both to each other, and to two other classes of phospholipid-specific enzymes, bacterial cardiolipin synthases, and eukaryotic and bacterial phosphatidylserine synthases, indicating that these enzymes form an homologous family. This family is suggested also to include two Poxviridae proteins of unknown function (p37K and protein K4), a bacterial endonuclease (nuc), an Escherichia coli putative protein (o338) containing an N-terminal domain showing similarities with helicase motifs V and VI, and a Synechocystis sp. putative protein with a C-terminal domain likely to possess a DNA-binding function. Surprisingly, four regions of sequence similarity that occur once in nuc and o338, appear twice in all other homologues, indicating that the latter molecules are bi-lobed, having evolved from an ancestor or ancestors that underwent a gene duplication and fusion event. It is suggested that, for each of these enzymes, conserved histidine, lysine, aspartic acid, and/or asparagine residues may be involved in a two-step ping pong mechanism involving an enzyme-substrate intermediate.
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Affiliation(s)
- C P Ponting
- Fibrinolysis Research Unit, University of Oxford, United Kingdom.
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9
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Shen B, Nolan JP, Sklar LA, Park MS. Essential amino acids for substrate binding and catalysis of human flap endonuclease 1. J Biol Chem 1996; 271:9173-6. [PMID: 8621570 DOI: 10.1074/jbc.271.16.9173] [Citation(s) in RCA: 87] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Human flap endonuclease 1 (FEN-1) is a member of the structure-specific endonuclease family and is involved in DNA repair. Eight restrictively conserved amino acids in FEN-1 have been converted individually to an alanine to elucidate their roles in specific DNA substrate binding and catalysis. Flap endonuclease activity of the wild type and mutant enzymes was measured by kinetic flow cytometry. Mutants D34A, D86A, and D181A lost their cleavage activity completely but retained substrate binding ability, as measured by their ability to inhibit the wild type enzyme in a competition assay. This indicates that these amino acids contribute to integrity of the enzyme active site. Loss of both binding and cleavage competency for the flap substrate by mutants E156A, G231A, and D233A suggests that these amino acids are involved in substrate binding. Mutants R103A and D179A retained wild type-like enzyme activity.
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Affiliation(s)
- B Shen
- Life Sciences Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
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10
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Vipond IB, Baldwin GS, Halford SE. Divalent metal ions at the active sites of the EcoRV and EcoRI restriction endonucleases. Biochemistry 1995; 34:697-704. [PMID: 7819265 DOI: 10.1021/bi00002a037] [Citation(s) in RCA: 109] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Restriction enzymes cannot cleave DNA without a metal ion cofactor. The specificities of the EcoRV and EcoRI endonucleases for metals were studied by measuring DNA cleavage rates with several metal ions and with combinations of metal ions. Both EcoRV and EcoRI had optimal activities with Mg2+, were less active with several other ions including Mn2+, and had virtually no activity with Ca2+. But the activities of EcoRV and EcoRI with either Mg2+ or Mn2+ were perturbed by Ca2+. For EcoRI, both Mg2+- and Mn(2+)-dependent activities, at both cognate and noncognate sites, were all inhibited by Ca2+. The activity of EcoRV at its recognition site with Mg2+ was also inhibited by Ca2+. But the Mn(2+)-dependent reaction at the EcoRV recognition site was stimulated by Ca2+. EcoRV activities at noncognate sites with either Mg2+ or Mn2+ displayed a biphasic response to Ca2+: stimulation at low concentrations of Ca2+ and inhibition at high concentrations. These observations, together with the known structures of the proteins, indicate that EcoRI needs only one metal ion per active site and is inactive when Mg2+ is displaced by Ca2+, while EcoRV needs two and that the displacement of one by Ca2+ can enhance activity. We propose a mechanism for phosphodiester hydrolysis by EcoRV that involves two metal ions.
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Affiliation(s)
- I B Vipond
- Department of Biochemistry, University of Bristol, U.K
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11
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Christiansen K, Knudsen B, Westergaard O. The covalent eukaryotic topoisomerase I-DNA intermediate catalyzes pH-dependent hydrolysis and alcoholysis. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(19)78134-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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12
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Heydenreich A, Koellner G, Choe HW, Cordes F, Kisker C, Schindelin H, Adamiak R, Hahn U, Saenger W. The complex between ribonuclease T1 and 3'GMP suggests geometry of enzymic reaction path. An X-ray study. EUROPEAN JOURNAL OF BIOCHEMISTRY 1993; 218:1005-12. [PMID: 8281918 DOI: 10.1111/j.1432-1033.1993.tb18459.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The crystal structure of the complex between ribonuclease T1 and 3'GMP suggests that (a) a substrate GpN is bound to the active site of ribonuclease T1 in a conformation that actively supports the catalytic process, (b) the reaction occurs in an in-line process, (c) His40 N epsilon H+ activates O2'-H, (d) Glu58 carboxylate acts as base and His92 N epsilon H+ as acid in a general acid-base catalysis. The crystals have the monoclinic space group P2(1), a = 4.968 nm, b = 4.833 nm, c = 4.048 nm, beta = 90.62 degrees with two molecules in the asymmetric unit. The structure was determined by molecular replacement and refined to R = 15.3% with 11,338 data > or = 1 sigma (Fo) in the resolution range 1.0-0.2 nm; this includes 180 water molecules and two Ca2+. The structure of ribonuclease T1 is as previously observed. 3'GMP is bound in syn conformation; guanine is located in the specific recognition site, the ribose adopts C4'-exo puckering, the ribose phosphate is extended with torsion angle epsilon in trans. The O2'-H group is activated by accepting and donating hydrogen bonds from His40 N epsilon H+ and to Glu58 O epsilon 1; the phosphate is hydrogen bonded to Glu58 O epsilon 2H, Arg77 N epsilon H+ and N eta 2H+, Tyr38 O eta H, His92 N eta H+. The conformation of ribose phosphate is such that O2' is at a distance of 0.31 nm from phosphorus, and opposite the P-OP3 bond which accepts a hydrogen bond from His92 N epsilon H+; we infer from a model building study that this bond is equivalent to the scissile P-O5' in a substrate GpN.
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Affiliation(s)
- A Heydenreich
- Institut für Kristallographie, Freie Universität Berlin, Germany
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13
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Meiering EM, Bycroft M, Lubienski MJ, Fersht AR. Structure and dynamics of barnase complexed with 3'-GMP studied by NMR spectroscopy. Biochemistry 1993; 32:10975-87. [PMID: 8218163 DOI: 10.1021/bi00092a006] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The binding of 3'-GMP to the ribonuclease, barnase, has been studied using heteronuclear 2D and 3D NMR spectroscopy. The 1H and 15N NMR spectra of barnase complexed with 3'-GMP have been assigned. 2D and 3D NOESY spectra have been used to identify inter- and intramolecular NOEs, and a solution structure for the barnase-3'-GMP complex has been calculated. The position of the guanine ring of the ligand is reasonably well defined in the structures. The guanine ring forms hydrogen bonds with the NH protons of Ser57 and Arg59. These residues are located in a loop that is conserved among the microbial guanine-specific ribonucleases. The 2'-hydroxyl of 3'-GMP is close to His102 and Glu73, which have been shown to be involved in catalysis. The phosphate group of 3'-GMP is close to a number of positively charged residues that have also been shown to be important for activity. The position of the sugar moiety of 3'-GMP is less well defined in the structures. Structures calculated for the complex could not simultaneously satisfy all the observed intermolecular NOEs for the sugar protons, suggesting that the sugar samples several conformations when bound to barnase. The binding of 3'-GMP to barnase in solution is similar to that observed in the crystal structures of nucleotides bound to related ribonucleases. 3'-GMP binding causes no major conformational change in barnase. In contrast to the small structural changes that occur, there is a significant decrease in the rates of hydrogen/deuterium exchange and aromatic ring rotation in the active site of barnase upon ligand binding.
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Affiliation(s)
- E M Meiering
- MRC Unit for Protein Function and Design, Cambridge IRC for Protein Engineering, U.K
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15
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Lin J, Phillips A, Hearst J, Sancar A. Active site of (A)BC excinuclease. II. Binding, bending, and catalysis mutants of UvrB reveal a direct role in 3‘ and an indirect role in 5‘ incision. J Biol Chem 1992. [DOI: 10.1016/s0021-9258(19)37098-x] [Citation(s) in RCA: 76] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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16
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Active site of (A)BC excinuclease. I. Evidence for 5' incision by UvrC through a catalytic site involving Asp399, Asp438, Asp466, and His538 residues. J Biol Chem 1992. [DOI: 10.1016/s0021-9258(19)37097-8] [Citation(s) in RCA: 95] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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18
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Martinez-Oyanedel J, Choe HW, Heinemann U, Saenger W. Ribonuclease T1 with free recognition and catalytic site: crystal structure analysis at 1.5 A resolution. J Mol Biol 1991; 222:335-52. [PMID: 1960730 DOI: 10.1016/0022-2836(91)90215-r] [Citation(s) in RCA: 119] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The free form of ribonuclease T1 (RNase T1) has been crystallized at neutral pH, and the three-dimensional structure of the enzyme has been determined at 1.5 A nominal resolution. Restrained least-squares refinement yielded an R value of 14.3% for 12,623 structure amplitudes. The high resolution of the structure analysis permits a detailed description of the solvent structure around RNase T1, the reliable rotational setting of several side-chain amide and imidazole groups and the identification of seven disordered residues. Among these, the disordered and completely internal Val78 residue is noteworthy. In the RNase T1 crystal structures determined thus far it is always disordered in the absence of bound guanosine, but not in its presence. A systematic analysis of hydrogen bonding reveals the presence in RNase T1 of 40 three-center and an additional seven four-center hydrogen bonds. Three-center hydrogen bonds occur predominantly in the alpha-helix, where their minor components close 3(10)-type turns, and in beta-sheets, where their minor components connect the peptide nitrogen and carbonyl functions of the same residue. The structure of the free form is compared with complexes of RNase T1 with filled base recognition site and/or catalytic site. Several structural rearrangements occurring upon inhibitor or substrate binding are clearly apparent. In conjunction with the available biochemical knowledge, they are used to describe probable steps occurring early during RNase T1-catalyzed phosphate transesterification.
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