title: Identification of a novel binding motif in Pyrococcus furiosus DNA ligase for the functional interaction with proliferating cell nuclear antigen.
abstract: DNA ligase is an essential enzyme for all organisms and catalyzes a nick-joining reaction in the final step of the DNA replication, repair, and recombination processes. Herein, we show the physical and functional interaction between DNA ligase and proliferating cell nuclear antigen (PCNA) from the hyperthermophilic Euryarchaea Pyrococcus furiosus. The stimulatory effect of P. furiosus PCNA on the enzyme activity of P. furiosus DNA ligase was observed not at low ionic strength, but at a high salt concentration, at which a DNA ligase alone cannot bind to a nicked DNA substrate. On the basis of mutational analyses, we identified the amino acid residues that are critical for PCNA binding in a loop structure located in the N-terminal DNA-binding domain of P. furiosus DNA ligase. We propose that the pentapeptide motif QKSFF is involved in the PCNA-interacting motifs, in which Gln and the first Phe are especially important for stable binding with PCNA.
authors.affiliation: Department of Genetic Resources Technology, Faculty of Agriculture, Kyushu University, Japan.
authors.forename: Shinichi
authors.initials: S
authors.lastname: Kiyonari
authors.forename: Kohei
authors.initials: K
authors.lastname: Takayama
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Nishida
authors.forename: Yoshizumi
authors.initials: Y
authors.lastname: Ishino
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D001665:Binding Sites; D020134:Catalytic Domain; D004247:DNA / Q000378:metabolism; D000072481:DNA Ligase ATP; D011088:DNA Ligases / Q000737:chemistry* / Q000502:physiology; D008969:Molecular Sequence Data; D011189:Potassium Chloride / Q000494:pharmacology; D018809:Proliferating Cell Nuclear Antigen / Q000737:chemistry / Q000502:physiology*; D020027:Pyrococcus furiosus / Q000201:enzymology*
chemical_list: D018809:Proliferating Cell Nuclear Antigen; D011189:Potassium Chloride; D004247:DNA; D011088:DNA Ligases; D000072481:DNA Ligase ATP