Nucleotide sequence and expression of an extracellular hemolysin gene of Aeromonas hydrophila

Microb Pathog. 1991 Sep;11(3):189-97. doi: 10.1016/0882-4010(91)90049-g.


The extracellular hemolysin (AHH1) gene of Aeromonas hydrophila ATCC7966 was cloned into Charomid9-28 in Escherichia coli DH1, and its complete nucleotide sequence determined. Escherichia coli carrying this gene expressed an extracellular heat-labile hemolysin for rabbit red blood cells. The minimum size of the coding region of the 2.6 kilobase-pair BamHI-SphI fragment was subcloned into pUC118 and pUC119, selecting for hemolytic activity. The nucleotide sequence of this region contained a single open reading frame of 1734 base pairs, corresponding to a protein of 577 amino acid residues (63,658 daltons). A consensus promoter sequence was present upstream of the AHH1 open reading frame. Maxicell analysis of [35S]methionine-labelled proteins in E. coli CSR603 carrying the AHH1 plasmid suggested that AHH1 gene codes for an approximately 60,000 dalton polypeptide. By colony DNA-DNA hybridization analysis, the AHH1 gene was detected in 43 of 62 hemolysin-producing strains of A. hydrophila (isolated from various sources and areas) and in all 43 hemolysin-producing strains of A. salmonicida (isolated from fish). Three hemolysin-negative strains of A. hydrophila did not react with the AHH1 probe, whereas three non-hemolytic A. salmonicida strains hybridized with the probe.

MeSH terms

  • Aeromonas hydrophila / genetics*
  • Amino Acid Sequence
  • Bacterial Toxins / genetics*
  • Base Sequence
  • Cloning, Molecular
  • Escherichia coli / genetics
  • Genetic Variation
  • Molecular Sequence Data
  • Pore Forming Cytotoxic Proteins
  • Recombinant Proteins
  • Regulatory Sequences, Nucleic Acid
  • Restriction Mapping


  • Bacterial Toxins
  • Pore Forming Cytotoxic Proteins
  • Recombinant Proteins
  • aerolysin