title: One-step RNA pathogen detection with reverse transcriptase activity of a mutated thermostable Thermus aquaticus DNA polymerase.
abstract: We describe the cloning and characterization of a mutated thermostable DNA polymerase from Thermus aquaticus (Taq) that exhibits an increased reverse transcriptase activity and is therefore designated for one-step PCR pathogen detection using established real-time detection methods. We demonstrate that this Taq polymerase mutant (Taq M1) has similar PCR sensitivity and nuclease activity as the respective Taq wild-type DNA polymerase. In addition, and in marked contrast to the wild-type, Taq M1 exhibits a significantly increased reverse transcriptase activity especially at high temperatures (>60 degrees C). RNA generally hosts highly stable secondary structure motifs, such as hairpins and G-quadruplexes, which complicate, or in the worst case obviate, reverse transcription (RT). Thus, RT at high temperatures is desired to weaken or melt secondary structure motifs. To demonstrate the ability of Taq M1 for RNA detection of pathogens, we performed TaqMan probe-based diagnostics of Dobrava viruses by one-step RT-PCR. We found similar detection sensitivities compared to commercially available RT-PCR systems without further optimization of reaction parameters, thus making this enzyme highly suitable for any PCR probe-based RNA detection method.
authors.affiliation: Department of Chemistry and Konstanz Research School Chemical Biology, University of Konstanz, Konstanz, Germany.
authors.forename: Ramon
authors.initials: R
authors.lastname: Kranaster
authors.forename: Matthias
authors.initials: M
authors.lastname: Drum
authors.forename: Nicole
authors.initials: N
authors.lastname: Engel
authors.forename: Manfred
authors.initials: M
authors.lastname: Weidmann
authors.forename: Frank T
authors.initials: FT
authors.lastname: Hufert
authors.forename: Andreas
authors.initials: A
authors.lastname: Marx
mesh_terms: D006476:Orthohantavirus / Q000302:isolation & purification; D008958:Models, Molecular; D009154:Mutation; D009690:Nucleic Acid Conformation; D012367:RNA, Viral / Q000302:isolation & purification*; D012194:RNA-Directed DNA Polymerase / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D015203:Reproducibility of Results; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods*; D019914:Taq Polymerase / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism
chemical_list: D012367:RNA, Viral; D019914:Taq Polymerase; D012194:RNA-Directed DNA Polymerase