Stereochemistry of the biosynthesis of sn-2,3-O-diphytanyl glycerol, membrane lipid of archaebacteria Halobacterium halobium

Isoprenoid biosynthesis in bacteria: a novel pathway for the early steps leading to isopentenyl diphosphate

“…Although the radioactivity has usually not been localized, the incorporation of 14C and, in one case of 13C labelled mevalonate into bacterial isoprenoids of different series (C30 and C40 carotenoids, acyclic polyprenol derivatives, isopentenyladenosine, sterols), is also in favour of the occurrence of the classical pathway [33][34][35][36][37][38][39][40][41][42][43][44]. This pathway is also present in the Archaebacteria examined so far, as shown by the incorporation of labelled acetate, mevalonate, glycerol or glucose into the lipids containing phytanyl chains of the thermoacidophilic Caldariella acidophila [4] or the halophilic Halobacterium species [45][46][47][48] and by the conversion of HMG-CoA into MVA by enzymic preparations from the latter bacteria [49]. In contrast, the negative results obtained after tentative incorporation of expected intermediates such as acetate or mevalonate or the poor incorporation rates are against the presence of the classical route in several other bacteria [50][51][52][53] test, the failure to incorporate mevalonate into the isoprenoids from bacteria, some of which have been clearly found to possess the novel pathway (e.g.…”

REVIEW: Metabolic Engineering of Isoprenoids

“…Many species of bacteria have been shown to utilize the G3PÂpyruvate pathway for isoprenoid biosynthesis, but the MVA pathway is also used in some bacteria. Labeling experiments have proved the MVA pathway exists in Staphylcoccus carnosus (Horbach et al, 1993), Myxococcus fulvus (Lois et al, 1998), Chloroflexus aurantiacus (Rieder et al, 1998) and several species of archaebacteria (Moldoveanu and Kates, 1988;Kakinuma et al, 1988;Eguchi et al, 1998). In addition to labeling studies, two metabolic inhibitors are available to help establish the identity of the operative pathway, mevinolin for the MVA pathway and fosmidomycin for the pyruvateÂG3P pathway.…”

sn -Glycerol-1-Phosphate-Forming Activities in Archaea : Separation of Archaeal Phospholipid Biosynthesis and Glycerol Catabolism by Glycerophosphate Enantiomers

“…autotroph Methanobacterium thermoautotrophicum is not known. Earlier work (3,5) based on the results of in vivo incorporation experiments for the formation of enantiomeric backbone of phospholipids in H. cutirubrum can be explained as follows. Isotopically labeled glycerol incorporated into halobacterial cells would be phosphorylated to G-3-P by glycerol kinase.…”