title: AidC, a novel N-acylhomoserine lactonase from the potato root-associated cytophaga-flavobacteria-bacteroides (CFB) group bacterium Chryseobacterium sp. strain StRB126.
abstract: N-acylhomoserine lactones (AHLs) are used as quorum-sensing (QS) signal molecules by many gram-negative bacteria. We have reported that Chryseobacterium sp. strain StRB126, which was isolated from the root surface of potato, has AHL-degrading activity. In this study, we cloned and characterized the aidC gene from the genomic library of StRB126. AidC has AHL-degrading activity and shows homology to several metallo-β-lactamase proteins from Bacteroidetes, although not to any known AHL-degrading enzymes. Purified AidC, as a maltose-binding fusion protein, showed high degrading activity against all tested AHLs, whether short- or long-chain forms, with or without substitution at carbon 3. High-performance liquid chromatography (HPLC) analysis revealed that AidC functions as an AHL lactonase catalyzing AHL ring opening by hydrolyzing lactones. An assay to determine the effects of covalent and ionic bonding showed that Zn(2+) is important to AidC activity both in vitro and in vivo. In addition, the aidC gene could also be PCR amplified from several other Chryseobacterium strains. In conclusion, this study indicated that the aidC gene, encoding a novel AHL lactonase, may be widespread throughout the genus Chryseobacterium. Our results extend the diversity and known bacterial hosts of AHL-degrading enzymes.
authors.affiliation: Department of Material and Environmental Chemistry, Graduate School of Engineering, Utsunomiya University, Utsunomiya, Tochigi, Japan.
authors.forename: Wen-Zhao
authors.initials: WZ
authors.lastname: Wang
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Morohoshi
authors.forename: Nobutaka
authors.initials: N
authors.lastname: Someya
authors.forename: Tsukasa
authors.initials: T
authors.lastname: Ikeda
mesh_terms: D002265:Carboxylic Ester Hydrolases / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*; D002413:Cations, Divalent / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D045247:Chryseobacterium / Q000201:enzymology* / Q000235:genetics; D003001:Cloning, Molecular; D003067:Coenzymes / Q000378:metabolism; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D006868:Hydrolysis; D007783:Lactones / Q000378:metabolism; D008969:Molecular Sequence Data; D018517:Plant Roots / Q000382:microbiology; D011994:Recombinant Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D011198:Solanum tuberosum / Q000382:microbiology; D013379:Substrate Specificity; D015032:Zinc / Q000378:metabolism
chemical_list: D002413:Cations, Divalent; D003067:Coenzymes; D004269:DNA, Bacterial; D007783:Lactones; D011994:Recombinant Proteins; D002265:Carboxylic Ester Hydrolases; C432003:N-acyl homoserine lactonase; D015032:Zinc