Cyanobacteria and chloroplasts are believed to share a common ancestor, but synthetic pathways for membrane lipids are different. Lyso-phosphatidic acid (lyso-PA) is the precursor for the synthesis of all membrane lipids and synthesized by an acyl-ACP dependent glycerol-3-phosphate acyltransferase (GPAT) in chloroplasts. In cyanobacteria, GPAT genes are not found and, instead, genes coding for enzymes in the acyl-phosphate dependent lyso-PA synthetic pathway (plsX and plsY) are conserved. We report that the PlsX/Y dependent lyso-PA synthetic pathway is essential in cyanobacteria, but can be replaced by acyl-ACP dependent GPAT from Escherichia coli (plsB) and Arabidopsis thaliana (ATS1). Cyanobacteria thus display the capacity to accept enzymes from other organisms to synthesize essential components. This ability may have enabled them to evolve into current chloroplasts from their ancestral origins.

蓝细菌和叶绿体被认为具有共同的祖先，但是膜脂的合成途径是不同的。溶血磷脂酸（lyso-PA）是所有膜脂质合成的前体，由叶绿体中的酰基-ACP依赖性甘油-3-磷酸酰基转移酶（GPAT）合成。在蓝细菌中，找不到GPAT基因，而是保守了酰基磷酸依赖性lyso -PA合成途径（plsX和plsY）中编码酶的基因。我们报告说，依赖PlsX / Y的lyso-PA合成途径在蓝细菌中是必不可少的，但可以被来自大肠杆菌（plsB）和拟南芥（ATS1）的酰基ACP依赖的GPAT取代。）。蓝细菌因此表现出接受来自其他生物的酶以合成必需成分的能力。这种能力可能使他们能够从祖先演变成现在的叶绿体。