Substrate recognition and selectivity of plant glycerol-3-phosphate acyltransferases (GPATs) from Cucurbita moscata and Spinacea oleracea.

Stromal glycerol-3-phosphate acyltransferases (GPAT) are responsible for the selective incorporation of saturated and unsaturated fatty-acyl chains into chloroplast membranes, which is an important determinant of a plant's ability to tolerate chilling temperatures. The molecular mechanisms of plant chilling tolerance were elucidated by creating chimeric GPATs between squash (Cucurbita moscata, chilling-sensitive) and spinach (Spinacea oleracea, chilling-tolerant) and the results were interpreted using structural information on squash GPAT determined by X-ray crystallography at 1.55 A resolution.