You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is True about protein A of staph aureus: and explain in detail?
Ans. is 'b' i.e., Binds to Fc part of IgG(Ref: Ananthanarayan, 9th/e, p. 197, 198)* Protein A is a cell wall component of S aureus strains and is a bacterial surface protein called as microbial surface components recognizing adhesive matrix molecules (MSCRAMMs).Bacterial attachment to host cells is mediated by MSCRAMMs, and these are important virulence factors.Protein A of Staph aureus binds to Fc terminal of IgG (IgG 1, 2 and 4 but not IgG 3) and prevents opsono- phagocytosis by PMNs.* Protein A has become an important reagent in immunology and diagnostic laboratory technology; for example, protein A with attached IgG molecules directed against a specific bacterial antigen agglutinates bacteria that have that antigen ("conglutination").