title: msDNA-Ec48, the smallest multicopy single-stranded DNA from Escherichia coli.
abstract: Previously we have reported a novel bacterial reverse transcriptase (RT) from Escherichia coli ECOR58 strains in which the YXDD box was replaced with LVDD (J.-R. Mao, S. Inouye, and M. Inouye, Biochem. Biophys. Res. Commun. 227:489-493, 1996). Here we determined the structure of the multicopy single-stranded DNA (msDNA) produced by the RT. The msDNA was found to consist of a single-stranded DNA of 48 nucleotides in length, the shortest msDNA thus far identified from natural sources. The msDNA, the RT, and the retron are designated msDNA-Ec48, RT-Ec48, and retron-Ec48, respectively. On the basis of the structure of the msr gene, the RNA molecule of msDNA-Ec48 is predicted to be composed of 119 ribonucleotides; it is the longest RNA among the known msDNAs. Analysis of the DNA sequences flanking the retron indicates that retron-Ec48 is associated with a prophage related to phages P2 and P4.
authors.affiliation: Department of Biochemistry, Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey, Piscataway 08854, USA.
authors.forename: J R
authors.initials: JR
authors.lastname: Mao
authors.forename: S
authors.initials: S
authors.lastname: Inouye
authors.forename: M
authors.initials: M
authors.lastname: Inouye
mesh_terms: D000595:Amino Acid Sequence; D017901:Bacteriophage P2 / Q000235:genetics; D001483:Base Sequence; D004269:DNA, Bacterial / Q000235:genetics*; D004277:DNA, Single-Stranded / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics*; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D009876:Operon; D011533:Proviruses / Q000235:genetics; D012329:RNA, Bacterial / Q000235:genetics*; D012194:RNA-Directed DNA Polymerase / Q000378:metabolism*
chemical_list: D004269:DNA, Bacterial; D004277:DNA, Single-Stranded; D012329:RNA, Bacterial; C058681:msDNA; D012194:RNA-Directed DNA Polymerase