Approximately 50% of Helicobacter pylori isolates produce a cytotoxin in vitro that induces
vacuolation of eukaryotic cells. Screening a lambda ZapII library of H. pylori 60190
chromosomal fragments permitted the identification of a 3864-base pair (bp) open reading
frame (vacA) that encoded the vacuolating cytotoxin, and a> or= 567-bp upstream gene that
was homologous to Escherichia coli cysteinyl-tRNA synthetase. The sequence data suggest
that a 33-amino-acid leader sequence and a C-terminal peptide are cleaved from a 139-kDa …