Which of the Following is NOT a Subunit of Lipopolysaccharide

Question

Which of the following is NOT a subunit of lipopolysaccharide (LPS)?
A) O-specific polysaccharide
B) lipid A
C) core polysaccharide
D) M protein

Accepted Answer

M protein is not a subunit of LPS. It is a surface protein found in some gram-positive bacteria, like Streptococcus pyogenes. The three subunits of LPS are lipid A, core polysaccharide, and O-specific polysaccharide.