151
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Barany F, Gelfand DH. Cloning, overexpression and nucleotide sequence of a thermostable DNA ligase-encoding gene. Gene 1991; 109:1-11. [PMID: 1756968 DOI: 10.1016/0378-1119(91)90582-v] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Thermostable DNA ligase has been harnessed for the detection of single-base genetic diseases using the ligase chain reaction [Barany, Proc. Natl. Acad. Sci. USA 88 (1991) 189-193]. The Thermus thermophilus (Tth) DNA ligase-encoding gene (ligT) was cloned in Escherichia coli by genetic complementation of a ligts 7 defect in an E. coli host. Nucleotide sequence analysis of the gene revealed a single chain of 676 amino acid residues with 47% identity to the E. coli ligase. Under phoA promoter control, Tth ligase was overproduced to greater than 10% of E. coli cellular proteins. Adenylated and deadenylated forms of the purified enzyme were distinguished by apparent molecular weights of 81 kDa and 78 kDa, respectively, after separation via sodium dodecyl sulfate-polyacrylamide-gel electrophoresis.
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Affiliation(s)
- F Barany
- Department of Microbiology, Cornell University Medical College, New York, NY 10021
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152
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Myers TW, Gelfand DH. Reverse transcription and DNA amplification by a Thermus thermophilus DNA polymerase. Biochemistry 1991; 30:7661-6. [PMID: 1714296 DOI: 10.1021/bi00245a001] [Citation(s) in RCA: 333] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
A recombinant DNA polymerase derived from the thermophilic eubacterium Thermus thermophilus (Tth pol) was found to possess very efficient reverse transcriptase (RT) activity in the presence of MnCl2. Many of the problems typically associated with the high degree of secondary structure present in RNA are minimized by using a thermostable DNA polymerase for reverse transcription, and predominantly full-length products can be obtained. The cDNA can also be amplified in the polymerase chain reaction (PCR) with the same enzyme. The Tth pol was observed to be greater than 100-fold more efficient in a coupled RT/PCR than the analogous DNA polymerase from Thermus aquaticus (Taq pol). The sensitivity of the reactions performed by Tth pol allowed for the detection of ethidium bromide stained products starting with as little as 100 copies of synthetic cRNA. Similar results were also obtained with RNA from a Philadelphia-chromosome positive cell line. Detection of IL-1 alpha mRNA was possible starting with 80 pg of total cellular RNA. The ability of Tth pol to perform both reverse transcription and DNA amplification will undoubtedly prove useful in the detection, quantitation, and cloning of cellular and viral RNA.
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Affiliation(s)
- T W Myers
- PCR Division, Cetus Corporation, Emeryville, California 94608
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153
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Affiliation(s)
- F Barany
- Department of Microbiology, Hearst Microbiology Research Center, Cornell University Medical College, New York, NY 10021
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154
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Fahy E, Kwoh DY, Gingeras TR. Self-sustained sequence replication (3SR): an isothermal transcription-based amplification system alternative to PCR. PCR METHODS AND APPLICATIONS 1991; 1:25-33. [PMID: 1842917 DOI: 10.1101/gr.1.1.25] [Citation(s) in RCA: 114] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- E Fahy
- Salk Institute Biotechnology/Industrial Associates, San Diego, California 92186
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155
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de Koster HS, Kenter MJ, D'Amaro J, Luiten RM, Schroeijers WE, Giphart MJ, Termijtelen A. Positive correlation between oligonucleotide typing and T-cell recognition of HLA-DP molecules. Immunogenetics 1991; 34:12-22. [PMID: 1713190 DOI: 10.1007/bf00212307] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The identification of 19 different HLA-DPB1 sequences implicates the existence of more DP specificities than can be typed for with cellular methods. How many of the DP beta sequences can be specifically recognized by T cells, and which of the polymorphic regions can contribute to the specificity of allorecognition, is not known. In order to investigate the distribution and the immunological relevance of recently described DPB1 alleles, we have typed a panel of 98 randomly selected Dutch Caucasoid donors for the HLA-DPB1 locus by oligonucleotide typing. Comparison of the typing results with primed lymphocyte typing (PLT) defined DP specificities shows an extremely good correlation. Moreover, additional alleles could be defined by oligonucleotide typing reducing the number of DP blanks in the panel. By selecting the appropriate responder stimulator combinations we were able to show that distinctive PLT reagents against oligonucleotide defined specificities DPB1*0401, DPB1*0402, DPB1*0901, and DPB1*1301 can be generated. To investigate in more detail which part of the DP molecule is responsible for the specificity of T-cell recognition, T-cell clones were generated against HLA-DPw3. The clones were tested for the recognition of stimulators carrying DPB1 alleles which had been defined by oligonucleotide typing and sequence analyses and which differed in a variable degree from DPB1*0301. The recognition patterns demonstrated that differences of one amino acid in polymorphic regions situated either in the beta sheets or alpha helix of the hypothetical model of the HLA class II molecule can eliminate T-cell recognition. Furthermore, sequence analyses revealed a new DPB1 allele designated DPB1*Oos.
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Affiliation(s)
- H S de Koster
- Department of Immunohaematology and Blood Bank, University Hospital Leiden, The Netherlands
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156
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Abstract
Calmodulin is a small Ca(2+)-binding protein proposed to act as the intracellular Ca2+ receptor that translates Ca2+ signals into cellular responses. We have constructed mutant yeast calmodulins in which the Ca(2+)-binding loops have been altered by site-directed mutagenesis. Each of the mutant proteins has a dramatically reduced affinity for Ca2+; one does not bind detectable levels of 45Ca2+ either during gel filtration or when bound to a solid support. Furthermore, none of the mutant proteins change conformation even in the presence of high Ca2+ concentrations. Surprisingly, yeast strains relying on any of the mutant calmodulins not only survive but grow well. In contrast, yeast strains deleted for the calmodulin gene are not viable. Thus, calmodulin is required for growth, but it can perform its essential function without the apparent ability to bind Ca2+.
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Affiliation(s)
- J R Geiser
- Department of Biochemistry, University of Washington, Seattle 98195
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157
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Iwasaki H, Ishino Y, Toh H, Nakata A, Shinagawa H. Escherichia coli DNA polymerase II is homologous to alpha-like DNA polymerases. MOLECULAR & GENERAL GENETICS : MGG 1991; 226:24-33. [PMID: 2034216 DOI: 10.1007/bf00273583] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The Escherichia coli polB gene encodes DNA polymerase II and is regulated by the SOS system. We sequenced a 4081 nucleotide segment of the E. coli chromosome that contains the polB gene and its flanking regions. DNA polymerase II, as deduced from the DNA sequence, consists of 782 amino acids, has a molecular weight of 89,917, and is structurally homologous to alpha-like DNA polymerases, which include eukaryotic replicative DNA polymerases. Comparison of the sequences of the alpha-like DNA polymerases including E. coli DNA polymerase II showed that there were nine highly conserved regions, and we constructed an unrooted phylogenetic tree of the DNA polymerases based on the differences in these conserved regions. The DNA polymerases of herpes groups viruses and the DNA polymerases that use protein priming for the initiation of replication form two separate subfamilies that occupy opposite locations in the tree. Other DNA polymerases, including E. coli DNA polymerase II, human DNA polymerase alpha, and yeast DNA polymerase I, occupy the central regions between the two subfamilies and they are rather distantly related to each other. The transcription initiation site of polB was identified by analysis of in vivo transcripts, and the promoter was assigned upstream of the polB coding region. The recognition sequence of the LexA repressor (SOS box) was identified by a footprinting experiment. It overlaps the -35 sequence of the polB promoter.
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Affiliation(s)
- H Iwasaki
- Department of Experimental Chemotherapy, Osaka University, Japan
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158
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Abstract
In addition to the general 3'-5' exonuclease domain described by Bernad et al. [Cell 59 (1989) 219-228] significant amino acid (aa) sequence similarity has been found in the C-terminal portion of 27 DNA-dependent DNA polymerases belonging to the two main superfamilies: (i) Escherichia coli DNA polymerase I (PolI)-like prokaryotic DNA polymerases, and (ii) DNA polymerase alpha-like prokaryotic and eukaryotic (viral and cellular) DNA polymerases. The six most conserved C-terminal regions, spanning approx. 340 aa, are located in the same linear arrangement and contain highly conserved motifs and critical residues involved in the polymerization function. According to the three-dimensional model of PolIk (Klenow fragment), these six conserved regions are located in the proposed polymerization domain, forming the metal and dNTP binding sites and the cleft for holding the DNA template. Site-directed mutagenesis in the phi 29 DNA polymerase supports some of these structural predictions. Therefore, it is likely that a 'Klenow-like core', containing the DNA polymerase and 3'-5' exonuclease activities, has evolved from a common ancestor, giving rise to the present-day prokaryotic and eukaryotic DNA polymerases.
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Affiliation(s)
- L Blanco
- Centro de Biología Molecular (CSIC-UAM), Universidad Autónoma, Madrid, Spain
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159
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Affiliation(s)
- W Bloch
- Cetus Corporation, Emeryville, California 94608
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160
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Joyce CM. Can DNA polymerase I (Klenow fragment) serve as a model for other polymerases? Curr Opin Struct Biol 1991. [DOI: 10.1016/0959-440x(91)90020-t] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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161
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Sagner G, Rüger R, Kessler C. Rapid filter assay for the detection of DNA polymerase activity: direct identification of the gene for the DNA polymerase from Thermus aquaticus. Gene 1991; 97:119-23. [PMID: 1995422 DOI: 10.1016/0378-1119(91)90018-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
A method for rapid identification of DNA polymerase activity employing an activated DNA substrate covalently bound to nitrocellulose membranes is described. Samples containing DNA polymerase are spotted and the membranes are incubated in an appropriate polymerization buffer containing radioactively labelled dNTPs. By autoradiography of the dried filters, DNA polymerase activity can be directly identified. The method can be used for fast and large-scale screening of chromosomal expression libraries for heterologous DNA polymerases characterized by activity optima different from those of the host organisms. We have identified the gene of the thermostable DNA polymerase from Thermus aquaticus in an expression library of Escherichia coli.
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Affiliation(s)
- G Sagner
- Department of Genetics, Boehringer Mannheim GmbH, Penzberg, F.R.G
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162
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Bej AK, Mahbubani MH, Atlas RM. Amplification of nucleic acids by polymerase chain reaction (PCR) and other methods and their applications. Crit Rev Biochem Mol Biol 1991; 26:301-34. [PMID: 1718663 DOI: 10.3109/10409239109114071] [Citation(s) in RCA: 107] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The in vitro replication of DNA, principally using the polymerase chain reaction (PCR), permits the amplification of defined sequences of DNA. By exponentially amplifying a target sequence, PCR significantly enhances the probability of detecting target gene sequences in complex mixtures of DNA. It also facilitates the cloning and sequencing of genes. Amplification of DNA by PCR and other newly developed methods has been applied in many areas of biological research, including molecular biology, biotechnology, and medicine, permitting studies that were not possible before. Nucleic acid amplification has added a new and revolutionary dimension to molecular biology. This review examines PCR and other in vitro nucleic acid amplification methodologies--examining the critical parameters and variations and their widespread applications--giving the strengths and limitations of these methodologies.
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Affiliation(s)
- A K Bej
- Department of Biology, University of Alabama, Birmingham 35294
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163
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Huibregtse JM, Engelke DR. Direct sequence and footprint analysis of yeast DNA by primer extension. Methods Enzymol 1991; 194:550-62. [PMID: 2005808 DOI: 10.1016/0076-6879(91)94042-b] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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164
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Main BF, Jones PJ, MacGillivray RT, Banfield DK. Apolipoprotein E genotyping using the polymerase chain reaction and allele-specific oligonucleotide primers. J Lipid Res 1991. [DOI: 10.1016/s0022-2275(20)42257-6] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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165
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Ludlow JM, Clark DS. Engineering considerations for the application of extremophiles in biotechnology. Crit Rev Biotechnol 1991; 10:321-45. [PMID: 2070423 DOI: 10.3109/07388559109038214] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Biotechnology may soon take greater advantage of extremophiles--microorganisms that grow in high salt or heavy metal concentrations, or at extremes of temperature, pressure, or pH. These organisms and their cellular components are attractive because they permit process operation over a wider range of conditions than their traditional counterparts. However, extremophiles also present a number of challenges for the development of bioprocesses, such as slow growth, low cell yield, and high shear sensitivity. Difficulties inherent in designing equipment suitable for extreme conditions are also encountered. This review describes both the advantages and disadvantages of extremophiles, as well as the specialized equipment required for their study and application in biotechnology.
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Affiliation(s)
- J M Ludlow
- Department of Chemical Engineering, University of California, Berkeley 94720
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166
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Decorte R, Cassiman JJ. Detection of amplified VNTR alleles by direct chemiluminescence: application to the genetic identification of biological samples in forensic cases. EXS 1991; 58:371-90. [PMID: 1831164 DOI: 10.1007/978-3-0348-7312-3_28] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Minisatellite or variable number of tandem repeat (VNTR) regions contain such a high degree of polymorphism that they allow one to construct an individual-specific DNA "fingerprint". Analysis of these sequences by Southern blot however, consumes much DNA and is not applicable to degraded DNA samples often recovered from body-fluid stains found at crime scenes. The polymerase chain reaction (PCR) technique may overcome these problems. With oligonucleotide primers flanking the repeat region, amplification of the VNTR alleles followed by direct visualization on ethidium bromide-stained agarose gels is possible. In those cases were the PCR yield is too low for direct visualization, the product can be blotted to a nylon membrane and hybridized with a labelled internal probe. Alternatively, the PCR product can be biotinylated during amplification and visualized by direct chemiluminescence after Southern transfer. The remarkable sensitivity of the PCR technique has allowed the detection of genetic polymorphisms in single cells, hair roots and single sperm. A drawback of this very high sensitivity however is that special precautions have to be taken to prevent accidental contamination resulting in erroneous interpretation of the results.
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Affiliation(s)
- R Decorte
- Center for Human Genetics, University of Leuven, Belgium
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167
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Hollingsworth HC, Nossal NG. Bacteriophage T4 encodes an RNase H which removes RNA primers made by the T4 DNA replication system in vitro. J Biol Chem 1991. [DOI: 10.1016/s0021-9258(18)52376-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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168
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Engelke DR, Krikos A, Bruck ME, Ginsburg D. Purification of Thermus aquaticus DNA polymerase expressed in Escherichia coli. Anal Biochem 1990; 191:396-400. [PMID: 2085185 DOI: 10.1016/0003-2697(90)90238-5] [Citation(s) in RCA: 115] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
DNA polymerase from Thermus aquaticus has become a common reagent in molecular biology because of its utility in DNA amplification and DNA sequencing protocols. A simplified method is described here for isolating the recombinant Taq enzyme after overproduction in Escherichia coli. Purification requires 8 to 10 h and entails heat treating and clearing the E. coli lysate, followed by precipitation of the enzyme with polyethyleneimine and elution from Bio Rex 70 ion exchange resin in a single salt step. The resulting enzyme preparation contains a single, nearly homogeneous protein consistent with the previously established size of the Taq DNA polymerase in a yield of 40-50 mg of protein per liter of cell culture.
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Affiliation(s)
- D R Engelke
- Department of Biological Chemistry, University of Michigan, Ann Arbor 48109
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169
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Lin-Chao S, Brenner DG, Cohen SN. Rapid two-stage polymerase chain reaction amplification of chromosomal DNA segments in lysates made from monolayer cultures attached to microcarrier beads. Gene 1990; 93:293-6. [PMID: 2227440 DOI: 10.1016/0378-1119(90)90238-m] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
We describe a method for the rapid two-stage amplification and detection by ethidium bromide staining of chromosomal nucleotide (nt) sequences in lysates made directly from anchorage-dependent cells attached to microcarrier beads. The procedure circumvents the need for cell detachment steps prior to analysis, facilitates the collection, transfer, and manipulation of the cells being studied, and makes unnecessary the use of Southern-blot hybridization for identification of specific nt sequences present in a small fraction of cells within a heterogeneous population.
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Affiliation(s)
- S Lin-Chao
- Department of Genetics, Stanford University School of Medicine, CA 94305-5120
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170
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Jung GH, Leavitt MC, Schultz M, Ito J. Site-specific mutagenesis of PRD1 DNA polymerase: mutations in highly conserved regions of the family B DNA polymerase. Biochem Biophys Res Commun 1990; 170:1294-300. [PMID: 2202298 DOI: 10.1016/0006-291x(90)90534-t] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The PRD1 DNA polymerase is a small multifunctional enzyme containing three major conserved amino acid sequences shared by family B DNA polymerases. Thus, the PRD1 DNA polymerase provides an useful model system with which to study structure-function relationships of DNA polymerase molecules. In order to investigate the functional and structural roles of the highly conserved amino acid sequences, we have introduced mutations into each of the 3 conserved regions of the PRD1 DNA polymerase. Genetic complementation study as well as DNA polymerase assay indicated that each mutation inactivated DNA polymerase catalytic activity, but not the 3' to 5' exonuclease activity.
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Affiliation(s)
- G H Jung
- Department of Microbiology and Immunology, College of Medicine, University of Arizona, Tucson
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171
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Identification of residues critical for the polymerase activity of the Klenow fragment of DNA polymerase I from Escherichia coli. J Biol Chem 1990. [DOI: 10.1016/s0021-9258(18)77342-0] [Citation(s) in RCA: 209] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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172
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Li YC, Wang DP, Chiang JY. Regulation of cholesterol 7 alpha-hydroxylase in the liver. Cloning, sequencing, and regulation of cholesterol 7 alpha-hydroxylase mRNA. J Biol Chem 1990. [DOI: 10.1016/s0021-9258(19)38501-1] [Citation(s) in RCA: 163] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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173
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Tse WT, Forget BG. Reverse transcription and direct amplification of cellular RNA transcripts by Taq polymerase. Gene X 1990; 88:293-6. [PMID: 2347496 DOI: 10.1016/0378-1119(90)90047-u] [Citation(s) in RCA: 71] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
We report the ability of Taq polymerase to directly transcribe RNA templates in vitro. We have made use of this finding to develop a single-step protocol for amplification of RNA transcripts. The method was shown to require only subnanogram amounts of total cellular RNA as starting material. A microassay was developed in which RNA can be extracted from one drop of blood or 1000 cultured cells, and analyzed for the expression of a specific gene.
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Affiliation(s)
- W T Tse
- Department of Human Genetics, Yale University School of Medicine, New Haven, CT 06510
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174
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Pääbo S, Irwin DM, Wilson AC. DNA damage promotes jumping between templates during enzymatic amplification. J Biol Chem 1990. [DOI: 10.1016/s0021-9258(19)39621-8] [Citation(s) in RCA: 137] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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175
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176
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Arnheim N. The Polymerase Chain Reaction. GENETIC ENGINEERING 1990; 12:115-37. [PMID: 1369998 DOI: 10.1007/978-1-4613-0641-2_8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- N Arnheim
- University of Southern California, Los Angeles 90089-1340
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177
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Kricker MC, Tindall KR. Direct sequencing of bacteriophage T4 DNA with a thermostable DNA polymerase. Gene X 1989; 85:199-204. [PMID: 2620832 DOI: 10.1016/0378-1119(89)90481-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
We present a simple and convenient protocol for the direct sequencing of bacteriophage T4 genomic DNA. The method utilizes the thermostable DNA polymerase from Thermus aquaticus (Taq) and 32P-end-labeled oligodeoxyribonucleotide primers to produce extension products that allow the analysis of at least 200 nucleotides (nt) on a single sequencing gel. Single-nt changes in the template were easily detectable following an overnight exposure of the autoradiograms. Comparison of sequences from fully modified T4 DNA containing glucosylated hydroxymethyldeoxycytosine or from templates containing cytosine showed little difference in sequence clarity. These techniques considerably simplify the molecular analysis of T-even bacteriophages and should be compatible with automated sequencing methods which employ 5'-end-labeled primers.
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Affiliation(s)
- M C Kricker
- Laboratory of Molecular Genetics, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709
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178
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Bernad A, Blanco L, Lázaro JM, Martín G, Salas M. A conserved 3'----5' exonuclease active site in prokaryotic and eukaryotic DNA polymerases. Cell 1989; 59:219-28. [PMID: 2790959 DOI: 10.1016/0092-8674(89)90883-0] [Citation(s) in RCA: 366] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The 3'----5' exonuclease active site of E. coli DNA polymerase I is predicted to be conserved for both prokaryotic and eukaryotic DNA polymerases based on amino acid sequence homology. Three amino acid regions containing the critical residues in the E. coli DNA polymerase I involved in metal binding, single-stranded DNA binding, and catalysis of the exonuclease reaction are located in the amino-terminal half and in the same linear arrangement in several prokaryotic and eukaryotic DNA polymerases. Site-directed mutagenesis at the predicted exonuclease active site of the phi 29 DNA polymerase, a model enzyme for prokaryotic and eukaryotic alpha-like DNA polymerases, specifically inactivated the 3'----5' exonuclease activity of the enzyme. These results reflect a high evolutionary conservation of this catalytic domain. Based on structural and functional data, a modular organization of enzymatic activities in prokaryotic and eukaryotic DNA polymerases is also proposed.
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Affiliation(s)
- A Bernad
- Centro de Biologia Molecular (CSIC-UAM), Universidad Autónoma, Madrid, Spain
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