Sequence analysis by cloning of the structural gene of gassericin A, a hydrophobic bacteriocin produced by Lactobacillus gasseri LA39.
Gassericin A, a bacteriocin from Lactobacillus gasseri LA39, was purified to homogeneity from the culturesupernatant mainly by reverse-phase chromatography. The molecular weight of gassericin A was found to be 5,652 by mass analysis, unlike the estimated 3,800 found by SDS-PAGE. However, when the purified preparation was treated with lysylendopeptidase, it migrated as a single band to 5,600 with bacteriocin activity on SDS-PAGE. N- and C-terminal amino acids could not be identified. The internal amino acid could be identified after gassericin A was hydrolyzed with lysylendopeptidase. The DNA of the structural gene of gassericin A was sequenced by cloning of the gene from chromosomal DNA with an oligonucleotide probe. The structural gene of gassericin A was found on the chromosomal DNA as an open reading frame encoding a protein composed of 91 amino acids. The amino acid sequence of mature gassericin A was predicted to be 58 residues from the DNA sequence and results of mass analysis. These results suggested that gassericin A has a closed circular structure with N- and C-terminals linked. Gassericin A is a hydrophobic class II bacteriocin; it was 98% identical with acidocin B produced by Lactobacillus acidophilus M46.
Kawai
Y
Y
Laboratory of Animal Products Chemistry, Biological Resource Science, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan.
Saito
T
T
Suzuki
M
M
Itoh
T
T
D000595:Amino Acid Sequence; D000818:Animals; D001430:Bacteriocins / Q000737:chemistry / Q000235:genetics*; D001483:Base Sequence; D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000032:analysis*; D015964:Gene Expression Regulation, Bacterial; D006801:Humans; D007223:Infant; D007778:Lactobacillus / Q000378:metabolism*; D008969:Molecular Sequence Data; D017422:Sequence Analysis, DNA
D001430:Bacteriocins; D004269:DNA, Bacterial; C096679:gassericin A