title: Biological function of a DUF95 superfamily protein involved in the biosynthesis of a circular bacteriocin, leucocyclicin Q.
abstract: Biological functions of a DUF95 superfamily protein in the biosynthesis gene cluster of a novel circular bacteriocin, leucocyclicin Q (LcyQ), were characterized in this paper. Sequence analysis and database search of the regions flanking the LcyQ structural gene lcyQ revealed four open reading frames (lcyR, lcyB, lcyC, and lcyD) related to bacteriocin biosynthesis. LcyD shares some similarity to the DUF95 superfamily proteins, often found in the biosynthetic gene clusters of circular bacteriocins. Mass spectrometry analysis showed accumulation of active mature LcyQ inside lcyD knockout cells. Heterologous expression of lcyD demonstrated that it confers robust immunity against LcyQ. Peptide release/binding assay revealed that the immunity could be attributed to the secretion of LcyQ to the cell exterior. Thus, the DUF95 superfamily protein has a dual function in the biosynthesis of LcyQ, as an immunity-associated transporter and as a secretion-aiding agent. Accumulation of mature LcyQ inside the cell in lcyD knockout strains, further implied that cyclization occurs within the cell. To the best of our knowledge, this is the first report on LcyQ cyclization inside the cell and the dual role of a DUF95 superfamily protein in circular bacteriocin biosynthesis.
authors.affiliation: Laboratory of Microbial Technology, Division of Applied Molecular Microbiology and Biomass Chemistry, Department of Bioscience and Biotechnology, Faculty of Agriculture, Graduate School, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan.
authors.forename: Fuqin
authors.initials: F
authors.lastname: Mu
authors.affiliation: Laboratory of Microbial Technology, Division of Applied Molecular Microbiology and Biomass Chemistry, Department of Bioscience and Biotechnology, Faculty of Agriculture, Graduate School, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan.
authors.forename: Yoshimitsu
authors.initials: Y
authors.lastname: Masuda
authors.affiliation: Laboratory of Microbial Technology, Division of Applied Molecular Microbiology and Biomass Chemistry, Department of Bioscience and Biotechnology, Faculty of Agriculture, Graduate School, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Zendo
authors.affiliation: R&D Laboratories, Tokai Pickling Co. Ltd., 78-1 Mukaigo, Mukokusamacho, Toyohashi 441-8142, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ono
authors.affiliation: R&D Laboratories, Tokai Pickling Co. Ltd., 78-1 Mukaigo, Mukokusamacho, Toyohashi 441-8142, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kitagawa
authors.affiliation: R&D Laboratories, Tokai Pickling Co. Ltd., 78-1 Mukaigo, Mukokusamacho, Toyohashi 441-8142, Japan.
authors.forename: Haruo
authors.initials: H
authors.lastname: Ito
authors.affiliation: Laboratory of Microbial Technology, Division of Applied Molecular Microbiology and Biomass Chemistry, Department of Bioscience and Biotechnology, Faculty of Agriculture, Graduate School, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan.
authors.forename: Jiro
authors.initials: J
authors.lastname: Nakayama
authors.affiliation: Laboratory of Microbial Technology, Division of Applied Molecular Microbiology and Biomass Chemistry, Department of Bioscience and Biotechnology, Faculty of Agriculture, Graduate School, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan; Laboratory of Functional Food Design, Department of Functional Metabolic Design, Bio-Architecture Center, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan. Electronic address: sonomoto@agr.kyushu-u.ac.jp.
authors.forename: Kenji
authors.initials: K
authors.lastname: Sonomoto
mesh_terms: D000595:Amino Acid Sequence; D001430:Bacteriocins / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics / Q000276:immunology; D003500:Cyclization; D024881:Drug Resistance, Bacterial; D007934:Leuconostoc / Q000378:metabolism; D013058:Mass Spectrometry; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D005810:Multigene Family / Q000235:genetics*; D016366:Open Reading Frames / Q000235:genetics; D011485:Protein Binding; D017422:Sequence Analysis, DNA
chemical_list: D001430:Bacteriocins
keywords: Circular bacteriocin; Cyclization; Immunity; Leucocyclicin Q; Secretion