Abstract
In Synechocystis sp. PCC6803, sll1848 is a homologue of the plsC gene that encodes for 1-acylglycerol-3-phosphate acyltransferase (LPAAT) in E.coli. We obtained a disruptant of PCC6803 as to the sll1848, and analyzed it. This mutant decreased proportion of fatty acids with 16-carbon chain (C16) with an increase in that with 18-carbon chain (C18). These indicated that sll1848 is involved in determination of fatty acid composition. The transfer of an acyl group to the sn-2 position is catalyzed generally by LPAAT, and PCC6803 mainly has C16 fatty acids at the sn-2 position of glycerol moiety of glycerolipids. It is thus suggested that the protein encoded by sll1848 functions as LPAAT, and that the transfer of an acyl group to sn-2 position is replaceable by the gene other than sll1848. This mutant as compared with the wild type showed slower growth rate and higher sensitivity to a low temperature.
