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| Section2 = }} Lipid II is an amphipathic peptidoglycan precursor molecule involved in the synthesis of the cell wall of bacteria. The molecule is named for its bactoprenol hydrocarbon chain that acts as a lipid anchor, embedding itself in the bacterial cell membrane. The translocation of lipid II across the cell membrane is needed to incorporate its disaccharide-pentapeptide "building block" into peptidoglycan, making Lipid II the target of several antibiotics. ==Synthesis== ===In peptidoglycan biosynthetic pathway=== Lipid II is the final intermediate in peptidoglycan biosynthesis. It is formed when the transferase MurG catalyzes addition of ''N''-acetylglucosamine (GlcNAc) to Lipid I, resulting in a complete disaccharide-pentapeptide monomer with a bactoprenol-pyrophosphate anchor. This occurs on the interior of the cytoplasmic membrane, where the bactoprenol chain is embedded in the inner leaflet of the bilayer. Lipid II is then flipped across the membrane to expose the disaccharide-pentapeptide monomer, which is the pentapeptide stem consisting of L-Ala-γ-D-Glu-m-DAP-D-Ala-D-Ala between GlcNAc and ''N''-acetylmuramic acid (MurNAc), for polymerization and cross-linking into peptidoglycan. The remaining bactoprenol-pyrophosphate is then recycled to the interior of the membrane. Lipid II has been referred to as the “shuttle carrier” of peptidoglycan “building blocks”. The essential flippase that translocates lipid II across the cytoplasmic membrane was only published in July 2014, after decades of searching. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Lipid II」の詳細全文を読む スポンサード リンク
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