Gene cloning shows the alpha-toxin of Clostridium perfringens to contain both sphingomyelinase and lecithinase activities

Mol Gen Genet. 1989 Nov;219(3):453-60. doi: 10.1007/BF00259619.


The plc gene encoding the alpha-toxin (phospholipase C), an important virulence factor of Clostridium perfringens, has been cloned, sequenced and expressed in Escherichia coli. Transcriptional analysis of mRNAs produced in vivo by C. perfringens and E. coli, and in vitro using purified RNA polymerase from C. perfringens revealed that plc is transcribed constitutively from a single promoter situated about 100 nucleotides from the coding sequence. A T7 expression system was used to overproduce alpha-toxin in E. coli; enzymological studies with the amplified plc gene product unambiguously demonstrated that both lecithinase (phospholipase C) and sphingomyelinase activities were associated with this 43,000 dalton cytotoxin. The 370-residue alpha-toxin is haemolytic and shares sequence and functional homology with the two components of Bacillus cereus haemolysin, cereolysin AB, in which phospholipase C and sphingomyelinase activities are associated with different polypeptides.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Bacterial Toxins / genetics*
  • Base Sequence
  • Calcium-Binding Proteins*
  • Cloning, Molecular
  • Clostridium perfringens / enzymology
  • Clostridium perfringens / genetics*
  • Molecular Sequence Data
  • Phospholipases / genetics
  • Phospholipases / metabolism*
  • Phosphoric Diester Hydrolases / metabolism*
  • RNA, Messenger / genetics
  • Restriction Mapping
  • Sequence Homology, Nucleic Acid
  • Sphingomyelin Phosphodiesterase / genetics
  • Sphingomyelin Phosphodiesterase / metabolism*
  • Transcription, Genetic
  • Type C Phospholipases*


  • Bacterial Toxins
  • Calcium-Binding Proteins
  • RNA, Messenger
  • Phospholipases
  • Phosphoric Diester Hydrolases
  • Type C Phospholipases
  • Sphingomyelin Phosphodiesterase
  • alpha toxin, Clostridium perfringens