title: Expression and characterization of a novel reverse transcriptase of the LTR retrotransposon Tf1.
abstract: The LTR retrotransposon of Schizosacharomyces pombe, Tf1, has several distinctive properties that can be related to the unique properties of its reverse transcriptase (RT). Consequently, we expressed, purified and studied the recombinant Tf1 RT. This monomeric protein possesses all activities typical to RTs: DNA and RNA-dependent DNA polymerase as well as an inherent ribonuclease H. The DNA polymerase activity shows preference to Mn(+)(2) or Mg(+)(2), depending on the substrate used, whereas the ribonuclease H strongly prefers Mn(+)(2). The most outstanding feature of Tf1 RT is its capacity to add non-templated nucleotides to the 3'-ends of the nascent DNA. This is mainly apparent in the presence of Mn(+)(2), as is the noticeable low fidelity of DNA synthesis. In all, Tf1 RT has a marked infidelity in synthesizing DNA at template ends, a phenomenon that can explain, as discussed herein, some of the features of Tf1 replication in the host cells.
authors.affiliation: Department of Cell and Developmental Biology, Sackler School of Medicine, Tel-Aviv University, Tel-Aviv, 69978, Israel.
authors.forename: Noa
authors.initials: N
authors.lastname: Kirshenboim
authors.forename: Zvi
authors.initials: Z
authors.lastname: Hayouka
authors.forename: Assaf
authors.initials: A
authors.lastname: Friedler
authors.forename: Amnon
authors.initials: A
authors.lastname: Hizi
mesh_terms: D003001:Cloning, Molecular; D004247:DNA / Q000096:biosynthesis; D020536:Enzyme Activators / Q000494:pharmacology; D015870:Gene Expression; D008274:Magnesium / Q000378:metabolism; D008345:Manganese / Q000378:metabolism; D009711:Nucleotides / Q000378:metabolism; D021122:Protein Subunits; D012194:RNA-Directed DNA Polymerase / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism*; D018626:Retroelements / Q000235:genetics*; D016914:Ribonuclease H / Q000378:metabolism; D012568:Schizosaccharomyces / Q000201:enzymology* / Q000235:genetics
chemical_list: D020536:Enzyme Activators; D009711:Nucleotides; D021122:Protein Subunits; D018626:Retroelements; D008345:Manganese; D004247:DNA; D012194:RNA-Directed DNA Polymerase; D016914:Ribonuclease H; D008274:Magnesium