This enzyme is found primarily as a Zn2+-dependent form in archaea but a Ni2+-dependent form has been found in Gram-positive bacteria [7]. The Zn2+-dependent metalloenzyme is responsible for the formation of archaea-specific sn-glycerol-1-phosphate, the first step in the biosynthesis of polar lipids in archaea^. It is the enantiomer of sn-glycerol 3-phosphate, the form of glycerophosphate found in bacteria and eukaryotes. The other enzymes involved in the biosynthesis of polar lipids in archaea are EC 2.5.1.41 (phosphoglycerol geranylgeranyltransferase) and EC 2.5.1.42 (geranylgeranylglycerol-phosphate geranylgeranyltransferase), which together alkylate the hydroxy groups of glycerol 1-phosphate to give unsaturated archaetidic acid, which is acted upon by EC 2.7.7.67 (CDP-archaeol synthase) to form CDP-unsaturated archaeol. The final step in the pathway involves the addition of L-serine, with concomitant removal of CMP, leading to the production of unsaturated archaetidylserine [5]. Activity of the enzyme is stimulated by K+ [2].
