Teichoic acid 412937 221806697 2008-06-26T05:10:00Z 89.102.255.61 '''Teichoic acids''' (''cf.'' [[Classical Greek language|Greek]] τειχος, teichos, "wall") are polymers of glycerol phosphate or ribitol phospate linked via [[phosphodiester bonds]]. These acids can be found in the [[cell wall]] of [[gram-positive]] bacteria, such as ''[[Staphylococci]]'', ''[[Streptococci]]'', ''[[Bacillus]]'', ''[[Clostridium]]'', ''[[Corynebacterium]]'' and ''[[Listeria]]'', and appear to extend to the surface of the [[peptidoglycan]] layer. Teichoic acids are not found in the [[gram-negative]] bacteria. They can be either covalently bonded to [[N-Acetylmuramic acid|''N''-acetylmuramic acid]] of the peptidoglycan layer, linked to the plasma membrane [[lipids]] found in the [[cytoplasmic membrane]], or linked to a terminal D-alanine in the [[tetrapeptide]] cross-links between molecules of [[N-Acetylmuramic acid|''N''-acetylmuramic acid]]. The combined units comprised of teichoic acids and lipids are referred to as [[lipoteichoic acid]]s. Teichoic acids are negatively charged. and therefore contribute to the negative charge of the gram-positive cell wall. They may also provide structural support for the cell wall and act as antigen. Teichoic acids also assist in regulation of cell growth by limiting the ability of [[autolysins]] to break the β(1-4) bond between the ''N''-acetyl glucosamine and the ''N''-acetylmuramic acid. [[Category:Organic acids]] [[Category:Cell biology]] {{biochem-stub}} [[ca:Àcid teicoic]] [[da:Teikoidsyre]] [[de:Teichonsäuren]] [[es:Ácido teicoico]] [[fr:Acide teichoïque]]