title: AmiE, a novel N-acylhomoserine lactone acylase belonging to the amidase family, from the activated-sludge isolate Acinetobacter sp. strain Ooi24.
abstract: Many Gram-negative bacteria use N-acyl-l-homoserine lactones (AHLs) as quorum-sensing signal molecules. We have reported that Acinetobacter strains isolated from activated sludge have AHL-degrading activity. In this study, we cloned the amiE gene as an AHL-degradative gene from the genomic library of Acinetobacter sp. strain Ooi24. High-performance liquid chromatography analysis revealed that AmiE functions as an AHL acylase, which hydrolyzes the amide bond of AHL. AmiE showed a high level of degrading activity against AHLs with long acyl chains but no activity against AHLs with acyl chains shorter than eight carbons. AmiE showed homology with a member of the amidases (EC 3.5.1.4) but not with any known AHL acylase enzymes. An amino acid sequence of AmiE from Ooi24 showed greater than 99% identities with uncharacterized proteins from Acinetobacter ursingii CIP 107286 and Acinetobacter sp. strain CIP 102129, but it was not found in the draft or complete genome sequences of other Acinetobacter strains. The presence of transposase-like genes around the amiE genes of these three Acinetobacter strains suggests that amiE is transferred by a putative transposon. Furthermore, the expression of AmiE in Pseudomonas aeruginosa PAO1 reduced AHL accumulation and elastase activity, which were regulated by AHL-mediated quorum sensing.
authors.affiliation: Department of Material and Environmental Chemistry, Graduate School of Engineering, Utsunomiya University, Tochigi, Japan; JST, CREST, Kawaguchi, Japan.
authors.forename: Seiji
authors.initials: S
authors.lastname: Ochiai
authors.affiliation: Department of Material and Environmental Chemistry, Graduate School of Engineering, Utsunomiya University, Tochigi, Japan; JST, CREST, Kawaguchi, Japan.
authors.forename: Sera
authors.initials: S
authors.lastname: Yasumoto
authors.affiliation: Department of Material and Environmental Chemistry, Graduate School of Engineering, Utsunomiya University, Tochigi, Japan; JST, CREST, Kawaguchi, Japan morohosi@cc.utsunomiya-u.ac.jp.
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Morohoshi
authors.affiliation: Department of Material and Environmental Chemistry, Graduate School of Engineering, Utsunomiya University, Tochigi, Japan; JST, CREST, Kawaguchi, Japan.
authors.forename: Tsukasa
authors.initials: T
authors.lastname: Ikeda
mesh_terms: D000150:Acinetobacter / Q000145:classification / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification; D054742:Acyl-Butyrolactones / Q000378:metabolism*; D000581:Amidohydrolases / Q000235:genetics / Q000378:metabolism*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D003001:Cloning, Molecular; D015964:Gene Expression Regulation, Bacterial; D008969:Molecular Sequence Data; D010802:Phylogeny; D012722:Sewage / Q000382:microbiology*; D019895:Transposases / Q000235:genetics / Q000378:metabolism
chemical_list: D054742:Acyl-Butyrolactones; D001426:Bacterial Proteins; D012722:Sewage; D019895:Transposases; D000581:Amidohydrolases; C019665:amidase