Disease relevance of asr

• Plasmids containing asr DNA cloned from wild-type S. typhimurium conferred anaerobic prototrophy and the ability to produce hydrogen sulfide from sulfite on an Escherichia coli cys1 mutant [1].
• Sequence analysis and expression of the Salmonella typhimurium asr operon encoding production of hydrogen sulfide from sulfite [2].
• Transcriptional analysis of the acid-inducible asr gene in enterobacteria [3].
• We show here that transcription of the asr gene in Escherichia coli, Salmonella enterica serovar Typhimurium, Klebsiella pneumoniae and Enterobacter cloacae is strongly dependent on the acidification level of the growth medium, with maximal induction at pH 4.0-4.5 as determined by Northern hybridization analysis [3].

High impact information on asr

• Salmonella reduces tetrathionate to thiosulfate, which it can further reduce to H2S, by using enzymes encoded by the genes phs and asr [4].
• A chromosomal locus of Salmonella typhimurium which complements S. typhimurium asr (anaerobic sulfite reduction) mutants and confers on Escherichia coli the ability to produce hydrogen sulfide from sulfite was recently cloned (C. J. Huang and E. L. Barrett, J. Bacteriol. 172:4100-4102, 1990) [2].
• A second group of insertions, designated asr (anaerobic sulfite reduction), were located near map unit 53 on the S. typhimurium chromosome [1].
• Previous gene array analyses have also shown that asr is the most acid-induced gene in the E. coli genome [3].

References