Archaeal phospholipids: Structural properties and biosynthesis

• Published in: Biochimica et biophysica acta. Molecular and cell biology of lipids Vol. 1862; no. 11; pp. 1325 - 1339
• Main Authors: Caforio, Antonella, Driessen, Arnold J.M.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.11.2017
• Subjects: Archaea - metabolism; Archaeal lipids; Biosynthesis; Evolution, Molecular; Lipid chemical structures; Lipid divide; Lipogenesis; Membrane properties; Models, Molecular; Molecular Structure; Phospholipids - biosynthesis; Phospholipids - chemistry; Structure-Activity Relationship; Biosynthesis; Archaeal lipids; Membrane properties; Lipid divide; Lipid chemical structures
• DOI: 10.1016/j.bbalip.2016.12.006
• ISSN: 1388-1981; 1879-2618

Phospholipids are major components of the cellular membranes present in all living organisms. They typically form a lipid bilayer that embroiders the cell or cellular organelles, constitute a barrier for ions and small solutes and form a matrix that supports the function of membrane proteins. The chemical composition of the membrane phospholipids present in the two prokaryotic domains Archaea and Bacteria are vastly different. Archaeal lipids are composed of highly-methylated isoprenoid chains that are ether-linked to a glycerol-1-phosphate backbone while bacterial phospholipids consist of straight fatty acids bound by ester bonds to the enantiomeric glycerol-3-phosphate backbone. The chemical structure of the archaeal lipids and their compositional diversity ensures the required stability at extreme environmental conditions as many archaea thrive at such conditions including high or low temperature, high salinity and extreme acidic or alkaline pH values. However, not all archaea are extremophiles, and the presence of ether-linked phospholipids is a phylogenetic marker that distinguishes Archaea from other life forms. During the past decade, our understanding of the biosynthesis of archaeal lipids has progressed resulting in the characterization of the main biosynthetic steps of the pathway including the reconstitution of lipid biosynthesis in vitro. Here we describe the chemical and physical properties of archaeal lipids and membranes derived thereof, summarize the existing knowledge about the enzymology of the archaeal lipid biosynthetic pathway and discuss evolutionary theories associated with the “Lipid Divide” that resulted in the differentiation of bacterial and archaeal organisms. This article is part of a Special Issue entitled: Bacterial Lipids edited by Russell E. Bishop. [Display omitted] •Archaea represent the third domain of life.•Some Archaea thrive at the extremes of temperature, acidity and/or salinity.•Archaeal lipids consist of methylated isoprenoid chains ether-linked to glycerol-1-phosphate.•Ether lipids ensure membrane stability at extreme environmental conditions.•The ‘lipid divide’ among species raises intriguing questions about the origin of life.