Abstract
Gassericin A, a bacteriocin produced by Lactobacillus gasseri LA39, shows antibacterial activity against a number of Gram-positive food-borne pathogenic bacteria. Circularin A produced by Clostridium beijerinckii ATCC25752 is active against C. tyrobutyricum, a known cheese-spoilage bacterium. Both bacteriocins were purified to homogeneity from culture supernatants by reverse-phase chromatography and the subsequently determined amino acid sequences were used to clone the bacteriocin structural genes. Mature gassericin A and circularin A are class V circular bacteriocins comprised of 58 and 69 amino acid residues, respectively. Both bacteriocins are resistant to several peptidases and proteases, as are other cyclic bacteriocins. Heterologous expression of gassericin A in Escherichia coli was used to produce a non-cyclic mature peptide, which was shown to have a specific activity 173-fold lower than the circular molecule. The minimal region for production and secretion of active circularin A is comprised of five genes, as was deduced by heterologous gene expression in Enterococcus faecalis. Gassericin A and circularin A have limited mutual similarity in their primary sequences. Unlike most bacteriocins, including gassericin A, circularin A has a three-amino-acid-leader sequence.
Original language | English |
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Pages (from-to) | 393-398 |
Number of pages | 6 |
Journal | Current protein & peptide science |
Volume | 5 |
Issue number | 5 |
DOIs | |
Publication status | Published - Oct-2004 |
Keywords
- LACTOBACILLUS-ACIDOPHILUS GROUP
- LACTIC-ACID BACTERIA
- BUTYRIVIBRIO-FIBRISOLVENS AR10
- CLOSTRIDIUM-PERFRINGENS
- AMINO-ACID
- LACTACIN-F
- FUNCTIONAL-ANALYSIS
- GENETIC-ANALYSIS
- PEDIOCIN ACH
- REUTERI LA6