Disease relevance of cadA

• Unlike in Escherichia coli, V. cholerae cadB and cadA are also transcribed monocistronically [1].
• Representative strains of Shigella spp. and enteroinvasive E. coli displayed similar deletions of cadA [2].
• A second gene in the Staphylococcus aureus cadA cadmium resistance determinant of plasmid pI258 [3].
• Five 2,4-D degraders, including Bradyrhizobium and Sphingomonas strains, were found to have cadA gene homologs, suggesting that these 2,4-D degraders share 2,4-D degradation genes similar to those of strain HW13 cadABC [4].
• The cadC gene is needed in addition to cadA for full resistance to cadmium in S. aureus and Bacillus subtilis. cadC functions both in cis and in trans [3].

High impact information on cadA

• Comparison of the S. flexneri 2a and laboratory E. coli K-12 genomes in the region of cadA revealed a large deletion in Shigella [2].
• At acidic pH, the operon containing cadB and cadA, encoding lysine decarboxylase, was induced in the presence of lysine [5].
• Eight cadC mutants were isolated based on their ability to confer expression of a cadA-lacZ fusion independent of low external pH or exogenous lysine [6].
• Insertion sequences, a phage genome, and/or loci from different positions on the ancestral E. coli chromosome displaced the cadA locus to form distinct genetic linkages that are unique to each Shigella species [7].
• Previous studies demonstrated that the product of LDC activity, cadaverine, blocks the action of Shigella enterotoxins and that the gene encoding LDC, cadA, was abolished by large chromosomal deletions in each Shigella species [7].

Chemical compound and disease context of cadA

• Two open reading frames on a 3.7-kb BglII-XbaI fragment which encodes the Staphylococcus aureus cadA cadmium (and zinc) resistance determinant of plasmid pI258 were identified (G. Nucifora, L. Chu, T. K. Misra, and S. Silver, Proc. Natl. Acad. Sci. USA 86:3544-3548, 1989) [3].
• The cadA gene that encodes lysine decarboxylase in Escherichia coli is induced by low pH and - during anaerobic growth - by the substrate, lysine [8].
• Effect of chelating agents and respiratory inhibitors on regulation of the cadA gene in Escherichia coli [8].

Biological context of cadA

• The cadA ATPase of S. aureus plasmids is a 727 amino acid membrane ATPase that pumps Cd2+ from the cells as rapidly as it is accumulated [9].
• We have mapped the cadA gene at 92 min; the gene order is mel cadA groE ampA purA [10].
• They are negative for indole production, methyl red, H2S production on triple sugar-iron agar, urea hydrolysis, phenylalanine deamination, lysine decarboxylase, gelatin hydrolysis, and fermentation of adonitol, i-inositol, D-sorbitol, and raffinose [11].

Associations of cadA with chemical compounds

• Strains with fliC(H10) and fliC(H11), but not those with fliC(H8), retained intact cadA and cadC loci and decarboxylated lysine [12].
• Removal of 678 nucleotides from the 5' end of the published sequence (which includes the cadA promoter) abolished resistance to cadmium, whereas a 146-nucleotide-shorter deletion was without effect [3].
• This implies that the effect of chelating agents on cadA expression is mediated via the arcAB regulatory system [8].
• In an epidemic setting in South Africa, 406 xylose-negative and lysine-decarboxylase-negative isolates, collected from xylose-lysine-deoxycholate (XLD) agar, were tested for catalase [13].

References