Correlation Between Mutation Type and the Production of Cross-reacting Material in Mutants of the A Gene of the Histidine Operon in Salmonella typhimurium

摘要: This study concerns the correlation between type of mutation in a bacterial gene and ability mutant organism to produce immunologically cross-reacting material (CRM). Ninety-five mutants A histidine operon Salmonella typhimurium have been separated into three classes, by means mutagenesis suppression tests, according classification scheme devised H. J. Whitfield, Jr., et al.: (i) missense (in which there is single amino acid substitution protein); (ii) nonsense various portions carboxyl-terminal segment protein are missing); (iii) deletion frameshift mutants. Extracts all were also examined for presence CRM. At least 70% produced The genetic loci affected these randomly distributed throughout gene. None nonsense, deletion, or absence CRM keeping with finding that removal valine residue from carboxypeptidase eliminates antigenicity. Images