title: pT3.2I, the smallest plasmid of Thiobacillus T3.2.
abstract: The whole nucleotide sequence of pT3.2I, the smallest plasmid of the acidophilic bacterium Thiobacillus T3.2, has been determined. pT3.2I is 15,390 bp long with a 53.7% GC content. Different regions can be defined in it: one 2569-bp putative insertion sequence similar to other insertion sequences of some Agrobacterium Ti plasmids; and a longer sequence, which occurs in two almost identical copies, differing only in a 1-bp deletion (6406 and 6405 bp). Several open reading frames and some smaller sequences were found in this duplicated region: ORFA and ORFG, encoding a putative polyol dehydrogenase and a putative RepA replication protein, respectively, an 83-bp sequence which could code for an antisense RNA, and a 36-bp region highly homologous to ori sequences of ColE2- and ColE3-related plasmids. Another putative gene, ORFH, is only present in the longer copy of this region (it is deleted in the short copy) and might encode a 90-amino-acid polypeptide which could act as a second replication protein, RepB. Based on sequence comparisons, pT3. 2I can be related to plasmids in the pColE2-CA42 incB incompatibility group.
authors.affiliation: Department of Biochemistry and Molecular Biology, Complutense University of Madrid, Madrid, 28040, Spain.
authors.forename: T
authors.initials: T
authors.lastname: Aparicio
authors.forename: P
authors.initials: P
authors.lastname: Lorenzo
authors.forename: J
authors.initials: J
authors.lastname: Perera
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics; D001483:Base Sequence; D004265:DNA Helicases; D004261:DNA Replication; D004251:DNA Transposable Elements; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; D007064:L-Iditol 2-Dehydrogenase / Q000235:genetics; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D010957:Plasmids; D011506:Proteins / Q000235:genetics; D016372:RNA, Antisense; D018741:Replication Origin; D013855:Thiobacillus / Q000235:genetics*; D015534:Trans-Activators
chemical_list: D001426:Bacterial Proteins; D004251:DNA Transposable Elements; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; D011506:Proteins; D016372:RNA, Antisense; C048817:RepB protein, Bacteria; D015534:Trans-Activators; C045264:replication initiator protein; D007064:L-Iditol 2-Dehydrogenase; D004265:DNA Helicases