Incomplete activation of Escherichia coli hemolysin (HlyA) due to mutations in the 3' region of hlyC.
AUTOR(ES)
Guzmán-Verri, C
RESUMO
Mutational analysis of the carboxy-terminal region of Escherichia coli HlyC was performed by site-directed mutagenesis. Replacement of residue Val-127 or Lys-129 reduced the activity of HlyC to about 30 or 60%, respectively, of that of the wild type, while replacement of Gly-128 reduced the activity to less than 1% of the wild-type level. Complete inactivation of HlyC was caused by a double mutation, replacement of Gly-128 with valine and of Lys-129 with isoleucine. Analysis of culture supernatants from mutants with reduced hemolytic activity by two-dimensional gel electrophoresis revealed the production and simultaneous secretion of nonacylated, monoacylated, and fully acylated HlyA forms, demonstrating impairment of the acylation reaction, possibly due to a decreased affinity of HlyC for the individual HlyA acylation sites.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=179492Documentos Relacionados
- Analysis of the in vivo activation of hemolysin (HlyA) from Escherichia coli.
- Pathogenicity of an Enterotoxigenic Escherichia coli Hemolysin (hlyA) Mutant in Gnotobiotic Piglets†
- Calcium is required for binding of Escherichia coli hemolysin (HlyA) to erythrocyte membranes.
- Domains of Escherichia coli hemolysin (HlyA) involved in binding of calcium and erythrocyte membranes.
- Nonreciprocal complementation of the hlyC and lktC genes of the Escherichia coli hemolysin and Pasteurella haemolytica leukotoxin determinants.
