Genes encoding the N-acyl homoserine lactone-degrading enzyme are widespread in many subspecies of Bacillus thuringiensis.
Gram-negative bacteria can communicate with each other by N-acyl homoserine lactones (AHLs), which are quorum-sensing autoinducers. Recently, the aiiA gene (encoding an enzyme catalyzing the degradation of AHL) has been cloned from Bacillus sp. strain 240B1. During investigations in the course of the ongoing Bacillus thuringiensis subsp. morrisoni genome project, an aiiA homologue gene in the genome sequence was found. These results led to consideration of the possibility of the widespread existence of the gene in B. thuringiensis. aiiA homologue genes were found in 16 subspecies of B. thuringiensis, and their sequences were determined. Comparison of the Bacillus sp. strain 240B1 aiiA gene with the B. thuringiensis aiiA homologue genes showed high homologies of 89 to 95% and 90 to 96% in the nucleotide sequence and deduced amino acid sequence, respectively. Among the subspecies of B. thuringiensis having an aiiA gene, the subspecies aizawai, galleriae, kurstaki, kyushuensis, ostriniae, and subtoxicus were shown to degrade AHL. It was observed that recombinant Escherichia coli producing AiiA proteins also had AHL-degrading activity and could also attenuate the plant pathogenicity of Erwinia carotovora. These results indicate that insecticidal B. thuringiensis strains might have potential to compete with gram-negative bacteria in natural ecosystems by autoinducer-degrading activity.
Lee
Sang Jun
SJ
R&D Center, inBioNET Corporation, Daejeon 305-390, Korea.
Park
Sun-Yang
SY
Lee
Jung-Ju
JJ
Yum
Do-Young
DY
Koo
Bon-Tag
BT
Lee
Jung-Kee
JK
D015107:4-Butyrolactone / Q000031:analogs & derivatives* / Q000378:metabolism*; D000595:Amino Acid Sequence; D001413:Bacillus thuringiensis / Q000201:enzymology* / Q000235:genetics*; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D008666:Metalloendopeptidases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D016973:Pectobacterium carotovorum / Q000235:genetics / Q000472:pathogenicity; D010802:Phylogeny; D011994:Recombinant Proteins / Q000378:metabolism; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D011198:Solanum tuberosum / Q000382:microbiology
D001426:Bacterial Proteins; D011994:Recombinant Proteins; C088386:homoserine lactone; C406735:AiiA protein, Bacillus; D008666:Metalloendopeptidases; D015107:4-Butyrolactone