The Listeria monocytogenes gene ctpA encodes a putative P-type ATPase involved in copper transport.
A Tn917 transposon derivative was used to construct a lacZ transcriptional fusion mutant in Listeria monocytogenes DRDC8 that displayed increased beta-galactosidase activity in response to cation stress. A 4.3 kb fragment of L. monocytogenes chromosomal DNA flanking the lacZ fusion was cloned and sequenced. A 1962 bp open reading frame was identified, and designated ctpA. Analysis of the deduced 653 amino acid sequence revealed significant similarity to the family of ATP-dependent enzymes involved in copper transport in prokaryotes and eukaryotes. CtpA is distinctive by virtue of an N-terminal truncation in the domain responsible for cation binding. Growth of ctpA insertion mutants was restricted by the copper-chelating agent 8-hydroxyquinoline. DNA/RNA hybridisation studies revealed that levels of ctpA mRNA were increased following growth in media containing low and high copper concentrations. These results suggest the isolation of a region of DNA that encodes a novel copper-transporting system in L. monocytogenes.
Francis
M S
MS
Department of Microbiology and Immunology, University of Adelaide, South Australia.
Thomas
C J
CJ
D000251:Adenosine Triphosphatases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D000595:Amino Acid Sequence; D001483:Base Sequence; D001692:Biological Transport; D002462:Cell Membrane / Q000201:enzymology; D003300:Copper / Q000378:metabolism* / Q000494:pharmacology; D003470:Culture Media; D005798:Genes, Bacterial; D006706:Homeostasis; D008089:Listeria monocytogenes / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D015125:Oxyquinoline / Q000494:pharmacology; D011401:Promoter Regions, Genetic; D017510:Protein Folding; D012329:RNA, Bacterial / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic
D003470:Culture Media; D012329:RNA, Bacterial; D012333:RNA, Messenger; D015125:Oxyquinoline; D003300:Copper; D000251:Adenosine Triphosphatases