Cloning of dapD, aroD and asd of Leptospira interrogans serovar icterohaemorrhagiae, and nucleotide sequence of the asd gene
Baril, C.; Richaud, C.; Fournié, E.; Baranton, G.; Saint Girons, I.
Journal of General Microbiology 138(1): 47-53
1992
ISSN/ISBN: 0022-1287 PMID: 1348268 DOI: 10.1099/00221287-138-1-47
Accession: 007126241
Metabolites such as diaminopimelate and some aromatic derivatives, not synthesized in mammalian cells, are essential for growth of bacteria. As a first step towards the design of a new human live vaccine that uses attenuated strains of Leptospira interrogans, the asd, aroD and dapD genes, encoding aspartate .beta.-semialdehyde dehydrogenase, 3-dehydroquinase and tetrahydrodipicolinate N-succinyltransferase, respectively, were cloned by complementation of Escherichia coli mutants. The complete nucleotide sequence of the asd gene was determined and found to contain an open reading frame capable of encoding a protein of 349 amino acids with a calculated Mr of 38007. Comparison of this deduced L. interrogans aspartate .beta.-semialdehyde dehydrogenase amino acid sequence with those of the same enzyme from Saccharomyces cerevisiae and Corynebacterium glutamicum revealed 46% and 36% identity, respectively. By contrast, the identity between the L. interrogans enzyme and the Streptococcus mutans or E. coli enzymes was less than 31%. Highly conserved sequences within aspartate semialdehyde dehydrogenase from the five organisms were observed at the amino and carboxyl termini, and around the cysteine of the active site.