Abstract
Glycerol-3-phosphate acyltransferase (EC 2.3.1. 15; GPAT) catalyzes the committed step of the biosynthesis of glycerolipids in eubacteria and eukaryotes. Eukaryotes contain multiple genes for GPAT in their genome, which copes with the idea of symbiotic evolution of eukaryotic cells. GPAT activity localized in three cellular compartments in plant cells, i.e., ER, plastids and mitochondria, and the evolutionary relationship between the gene for plastid-targeted GPATs (ATS1) and that for cyanobacterial GPAT has attracted our major interest. However, our current knowledge of the gene for cyanobacterial GPAT is scarce. We herein conducted a comprehensive ProScan search for a conserved sequence motif of acyltransferases (Lewin et al. (1999) Biochemistry 38: 5764-5771) in the genome database of Synechocystis sp. PCC6803 and identified a putative acyltransferase gene that is probably a potent candidate for the ancestral gene for ATS1.
