Pseudopeptidoglycan (also known as pseudomurein^[1]) is a major cell wall component of some archaebacteria that differs from eubacterial peptidoglycan in chemical structure, but resembles eubacteria peptidoglycan in morphology, function, and structure. The basic components are N-acetylglucosamine and N-acetyltalosaminuronic acid (Peptidoglycan has N-acetylmuramic acid instead), which are linked by a β-1,3-glycosidic bond. Whenever pseudopeptidoglycan is present in an organism, lysozyme is ineffective. Lysozyme is a host defense mechanism, which can break the B-1,4-glycosidic bonds causing the peptidoglycan to become destroyed. However, pseudopeptidoglycan has the B-1,3-glycosidic bond rendering lysozyme useless.