Molecular analyses of the lactococcin A gene cluster from Lactococcus lactis subsp. lactis biovar diacetylactis WM4
| Autor: | G W Stoddard, M J van Belkum, Jan Kok, J P Petzel, Larry L. McKay |
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| Jazyk: | angličtina |
| Rok vydání: | 1992 |
| Předmět: |
DNA
Bacterial Molecular Sequence Data Restriction Mapping Sequence alignment Applied Microbiology and Biotechnology Restriction fragment Open Reading Frames Restriction map Adenosine Triphosphate Bacterial Proteins Bacteriocins Sequence Homology Nucleic Acid Gene cluster Amino Acid Sequence ORFS Genetics Ecology biology Base Sequence Lactococcus lactis Nucleic acid sequence Membrane Proteins biology.organism_classification Open reading frame Genes Bacterial Multigene Family biology.protein Carrier Proteins Food Science Biotechnology Research Article Plasmids |
| Popis: | The genes responsible for bacteriocin production and immunity in Lactococcus lactis subsp. lactis biovar diacetylactis WM4 were localized and characterized by DNA restriction fragment deletion, subcloning, and nucleotide sequence analysis. The nucleotide sequence of a 5.6-kb AvaII restriction fragment revealed a cluster with five complete open reading frames (ORFs) in the same orientation. DNA and protein homology analyses, combined with deletion and Tn5 insertion mutagenesis, implicated four of the ORFs in the production of and immunity to lactococcin A. The last two ORFs in the cluster were the lactococcin A structural and immunity genes, lcnA and lciA. The two ORFs immediately upstream of lcnA and lciA were designated lcnC and lcnD, and the proteins that they encoded showed similarities to proteins of signal sequence-independent secretion systems. lcnC encodes a protein of 716 amino acids that could belong to the HlyB family of ATP-dependent membrane translocators. LcnC contains an ATP binding domain in a conserved C-terminal stretch of approximately 200 amino acids and three putative hydrophobic segments in the N terminus. The lcnD product, LcnD, of 474 amino acids, is essential for lactococcin A expression and shows structural similarities to HlyD and its homologs. On the basis of these results, a secretion apparatus that is essential for the full expression of active lactococcin A is postulated. |
| Databáze: | OpenAIRE |
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