title: Primary structure of the DNA polymerase I gene of an alpha-proteobacterium, Rhizobium leguminosarum, and comparison with other family A DNA polymerases.
abstract: The structural gene for DNA polymerase I of Rhizobium leguminosarum was determined. The rhizobium DNA polymerase I consists of 1016 amino acid residues with a calculated molecular weight of 111,491 Dalton. The amino acid sequence comparison with E. coli DNA polymerase I, Thermus aquaticus DNA polymerase I, and Rickettsia prowazekii DNA polymerase I showed that, although 5'-nuclease and DNA polymerase domains are highly conserved, 3' to 5' exonuclease domains are much less conserved. While both R. leguminosarum and R. prowazekii belong to the alpha subdivision of the Proteobacteria on the basis of 16S ribosomal RNA phylogeny, the primary structure of the DNA polymerase I is quite different; the rhizobium DNA polymerase I has 3' to 5' proofreading exonuclease, but the rickettsia DNA polymerase I does not.
authors.affiliation: Department of Microbiology and Immunology, College of Medicine, The University of Arizona, Tucson, AZ 85724, USA.
authors.forename: Y P
authors.initials: YP
authors.lastname: Huang
authors.forename: J A
authors.initials: JA
authors.lastname: Downie
authors.forename: J
authors.initials: J
authors.lastname: Ito
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D003062:Codon; D004256:DNA Polymerase I / Q000737:chemistry* / Q000235:genetics*; D004259:DNA-Directed DNA Polymerase / Q000737:chemistry / Q000235:genetics; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D008970:Molecular Weight; D017434:Protein Structure, Tertiary; D016961:Rhizobium leguminosarum / Q000201:enzymology / Q000235:genetics*; D012283:Rickettsia prowazekii / Q000201:enzymology / Q000235:genetics; D016415:Sequence Alignment; D013824:Thermus / Q000201:enzymology / Q000235:genetics
chemical_list: D003062:Codon; D004256:DNA Polymerase I; D004259:DNA-Directed DNA Polymerase