Cloning and sequence analysis of the gene encoding Lactococcus lactis malolactic enzyme: Relationships with malic enzymes |
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Authors: | Muriel Denayrolles Michel Aigle Aline Lonvaud-Funel |
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Institution: | Institut d'Œnologie, Universitéde Bordeaux II, 351 cours de la Libération, 33405 Talence Cedex, France; Laboratoire de Génétique, CNRS URA 542, Universitéde Bordeaux II, Bordeaux, France |
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Abstract: | Abstract Malolactic enzyme is the key enzyme in the degradation of L-malic acid by lactic acid bacteria. Using degenerated primers designed from the first 20 N-terminal amino acid sequence of lactococcal malolactic enzyme, a 60-bp DNA fragment containing part of the mleS gene was amplified from Lactococcus lactis in a polymerase chain reaction. This specific probe was used to isolate two contiguous fragments covering the gene as a whole. The 1.9-kb region sequenced contains an open reading frame of 1623 bp, coding a putative protein of 540 amino acids. The deduced amino acid sequence reveals that lactococcal putative protein (Mlep) is highly homologous to the malic enzyme of other organisms. Expression of the mleS gene in Escherichia coli results in malolactic activity. |
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Keywords: | Lactococcus lactis Malolactic enzyme Malic acid metabolism Phylogeny MLE malolactic enzyme ME malic enzyme MLF malolactic fermentation LAB lactic acid bacteria LDH lactate dehydrogenase aa amino acid |
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