Asp 187 and Phe 190 residues in lethal factor are required for the expression of anthrax lethal toxin activity.
Anthrax toxin consists of three proteins, protective antigen, lethal factor, and edema factor. Protective antigen translocates lethal factor and edema factor to the cytosol of mammalian cells. The amino-termini of lethal factor and edema factor have several homologous stretches. These regions are presumably involved in binding to protective antigen. In the present study we have determined the role of one such homologous stretch in lethal factor. Residues 187AspLeuLeuPhe190 were replaced by alanine. Asp187Ala and Phe190Ala were found to be non-toxic in combination with protective antigen. Their protective antigen-binding ability was drastically reduced. We propose that Asp187 and Phe190 are crucial for the expression of anthrax lethal toxin activity.
Centre for Biotechnology, Jawaharlal Nehru University, New Delhi 110067, India.
Aparna
A
Singh
Vibha
V
Chauhan
Ajit
A
Sodhi
Rakesh
R
Bhatnagar
D000818:Animals; D000881:Anthrax / Q000382:microbiology*; D000942:Antigens, Bacterial; D001224:Aspartic Acid / Q000235:genetics; D001408:Bacillus anthracis / Q000235:genetics* / Q000472:pathogenicity; D001427:Bacterial Toxins / Q000235:genetics* / Q000378:metabolism; D002478:Cells, Cultured; D003600:Cytosol / Q000382:microbiology; D015964:Gene Expression Regulation, Bacterial; D007930:Leucine / Q000235:genetics; D008264:Macrophages / Q000166:cytology / Q000382:microbiology; D051379:Mice; D016296:Mutagenesis / Q000502:physiology; D009997:Osmotic Pressure; D010649:Phenylalanine / Q000235:genetics; D010957:Plasmids; D011485:Protein Binding; D014774:Virulence
D000942:Antigens, Bacterial; D001427:Bacterial Toxins; C030325:anthrax toxin; D001224:Aspartic Acid; D010649:Phenylalanine; D007930:Leucine