Analysis of protein A encoded by a mutated gene of Staphylococcus aureus Cowan I.
The protein A (spa) genes from Staphylococcus aureus Cowan I and a mutant strain of Cowan I called V-1 earlier suggested to produce a monovalent IgG-binding protein A have been cloned in Escherichia coli. The DNA sequences coding for the IgG-binding part of the spa genes from both strains have been determined and compared with each other and with a partial amino acid sequence of purified protein A from strain V-1. The nucleotide sequence of the spa gene from strain V-1 reveals an NH2-terminally located IgG-binding region homologous to region E first reported for strain 8325-4, region D and the major portion of region A. The amino acid sequence analysis of the purified protein A from this strain also shows the presence of regions E and D but only a minor part of region A. Reversed-phase high-performance liquid chromatography fractionation of purified protein A from strain V-1 revealed that the preparation was heterogeneous, containing mainly two peptides with different abilities to bind IgG molecules. A shuttle vector containing the cloned protein A gene from V-1 was constructed and transformed into different strains of S. aureus and the produced protein A was purified and analysed using sodium dodecyl sulfate/polyacrylamide gel electrophoresis.
D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D004269:DNA, Bacterial; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000235:genetics; D005798:Genes, Bacterial; D005822:Genetic Vectors; D006386:Hemagglutination Tests; D009154:Mutation; D009693:Nucleic Acid Hybridization; D013205:Staphylococcal Protein A / Q000032:analysis / Q000235:genetics*; D013211:Staphylococcus aureus / Q000235:genetics*
D004269:DNA, Bacterial; D013205:Staphylococcal Protein A