Ornithine lipids and their structural modifications: from A to E and beyond.
Ornithine lipids (OLs) are phosphorus-free membrane lipids that are widespread in eubacteria, but absent from archaea and eukaryotes. They contain a 3-hydroxy fatty acyl group attached in amide linkage to the α-amino group of the amino acid ornithine. A second fatty acyl group is ester-linked to the 3-hydroxy position of the first fatty acid. About 25% of the bacterial species whose genomes have been sequenced are predicted to have the capacity to form OLs. Distinct OL hydroxylations have been described in the ester-linked fatty acid, the amide-linked fatty acid, and the ornithine moiety. These modifications often seem to form part of a bacterial stress response to changing environmental conditions, allowing the bacteria to adjust membrane properties by simply modifying already existing membrane lipids without the need to synthesize new lipids.
Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, Mexico.
Miguel Á
MÁ
Vences-Guzmán
Otto
O
Geiger
Christian
C
Sohlenkamp
D001419:Bacteria / Q000737:chemistry / Q000201:enzymology / Q000378:metabolism*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D001692:Biological Transport; D008055:Lipids / Q000096:biosynthesis* / Q000737:chemistry*; D009952:Ornithine / Q000031:analogs & derivatives* / Q000096:biosynthesis / Q000737:chemistry
D001426:Bacterial Proteins; D008055:Lipids; C051524:ornithine containing aminolipid; D009952:Ornithine