The main function of Teichoic acids in Gram-positive bacteria is:
Gram positive wall comprises thick peptidoglycan crosslinked peptides providing rigidity against internal turgor up to 20 atmospheres. Embedded anionic polymers wall teichoic acids covalently linked phosphodiester to C6 hydroxyl N acetylmuramic acid and lipoteichoic acids anchored diacylglycerol into membrane extending outward. Structure polyglycerol phosphate or polyribitol phosphate modified D alanylation introducing positive charge modulating autolytic enzymes. Physiological roles encompass providing cell wall integrity by controlling autolysin Atl Atl mediated remodeling preventing premature lysis ensuring balanced expansion during growth, maintaining cation homeostasis binding magnesium essential for enzyme activity, influencing cationic antimicrobial peptide resistance by charge modification, serving phage receptor and adhesin for host colonization. Deletion tagO gene first step WTA synthesis lethal in Staphylococcus aureus without compensatory mutations highlighting essentiality. Unlike ion channels formed by proteins, teichoic acids not transporters nor replication regulators nor initiating peptidoglycan degradation but structural scaffolds regulating wall metabolism and physicochemical properties critical for survival in high osmolarity and immune evasion.
Ref: Brown et al., Nat Rev Microbiol 2013, Teichoic acids provide cell wall integrity in Gram-positive.