Identification of acetylated diether lipids in halophilic Archaea

Archaea-type ether lipids have been found recently in Bacillales. They are monoether lipids with a C35 isoprenoid chain and are diacetylated by theO-acetyltransferase YvoF. Phylogenetic studies implied that YvoF homologs also occur in Halobacteria (Archaea). Here we show that YvoF fromHaloferax volcanii has ether-lipid-specific acetyltransferase activity in vitro. Furthermore, we provide a mass spectrometric identification of acetylated archaeol and acetylated archaetidylglycerol inH. volcanii andHalobacterium salinarum for the first time. AbstractAs a hallmark of Archaea, their cell membranes are comprised of ether lipids. However, Archaea-type ether lipids have recently been identified in Bacteria as well, with a somewhat different composition: In Bacillales,sn-glycerol 1-phosphate is etherified with one C35 isoprenoid chain, which is longer than the typical C20 chain in Archaea, and instead of a second isoprenoid chain, the product heptaprenylglyceryl phosphate becomes dephosphorylated and afterward diacetylated by theO-acetyltransferase YvoF. Interestingly, database searches have revealed YvoF homologs in Halobacteria (Archaea), too. Here, we demonstrate that YvoF fromHaloferax volcanii can acetylate geranylgeranylglycerol in vitro. Additionally, we present the first-time identification of acetylated diether lipids inH. volcanii andHalobacterium salinarum by mass spectrometry. A variety of different acetylated lipids, namely acetylated archaeol, and acetylated archaetidyl...
Source: MicrobiologyOpen - Category: Microbiology Authors: Tags: ORIGINAL ARTICLE Source Type: research