title: An unusual bacterial reverse transcriptase having LVDD in the YXDD box from Escherichia coli.
abstract: A minor population of wild strains of Escherichia coli contains a gene for reverse transcriptase (RT) which is responsible for the synthesis of multicopy single-stranded DNA (msDNA), a branched DNA-RNA complex. A DNA fragment capable of synthesizing msDNA was cloned from strain ECOR-58, one of the 72 wild strains in the ECOR collection. The complete open reading frame of a novel reverse transcriptase, designated ECOR-58 RT, was identified. ECOR-58 RT consisted of 408 amino acid residues, and its 227-residue polymerase domain from residue 43 to 269 showed significant homologies to all the other bacterial RTs so far identified. Most significantly, its YXDD box, the most highly conserved sequence in all RTs from prokaryotes to eukaryotes, was found to be replaced with LVDD. ECOR-58 RT was found to be most distantly related in a phylogenetic tree to all 9 other bacterial RTs so far identified.
authors.affiliation: Department of Biochemistry, Robert Wood Johnson Medical School, Piscataway, New Jersey 08854, USA.
authors.forename: J R
authors.initials: JR
authors.lastname: Mao
authors.forename: M
authors.initials: M
authors.lastname: Inouye
authors.forename: S
authors.initials: S
authors.lastname: Inouye
mesh_terms: D000595:Amino Acid Sequence; D001419:Bacteria / Q000201:enzymology* / Q000235:genetics; D001483:Base Sequence; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics; D008969:Molecular Sequence Data; D010802:Phylogeny; D012194:RNA-Directed DNA Polymerase / Q000737:chemistry* / Q000235:genetics; D011994:Recombinant Proteins / Q000737:chemistry; D015183:Restriction Mapping; D017386:Sequence Homology, Amino Acid
chemical_list: D011994:Recombinant Proteins; D012194:RNA-Directed DNA Polymerase