A Study on the Biosynthesis of Protein A in Staphylococcus aureus

Protein A is a cell wall constituent of Staphylococcus aureus. After being synthesized on the ribosomes, the protein A molecules are linked to the peptidoglycan. This is a very rapid reaction which is completed within approximately 1 min; it is suggested that the molecules leave the ribosomes and are then directly incorporated into the peptidoglycan without passing a soluble cytoplasmic stage. The synthesis of protein A de novo and peptidoglycan take place independently of each other. Also, the incorporation of protein A into the cell wall proceeds when the synthesis of peptidoglycan has been completely inhibited by vancomycin, i.e. the synthesis of peptidoglycan is not essential for the incorporation of protein A. It is therefore concluded that protein A can be linked to pre‐existing peptidoglycan chains.