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. Enzymatic analysis of the chimeric GPATs showed that the chimeric GPATs containing the spinach region from residues 128 to 187 prefer the 18:1 unsaturated fatty acid rather than 16:0 saturated fatty acid. Structure analysis suggests that the size and character of the cavity that is formed from this region determines the specific recognition of acyl chains.
Tamada
Taro
T
Central Laboratories for Key Technology, Kirin Brewery Co. Ltd, Fukuura 1-13-5, Kanazawa-ku, Yokohama 236-0004, Japan.
Feese
Michael D
MD
Ferri
Stefano R
SR
Kato
Yoichi
Y
Yajima
Rieko
R
Toguri
Toshihiro
T
Kuroki
Ryota
R
D000595:Amino Acid Sequence; D018360:Crystallography, X-Ray; D028464:Cucurbita / Q000201:enzymology*; D018744:DNA, Plant / Q000737:chemistry / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics; D005227:Fatty Acids / Q000378:metabolism; D005992:Glycerol-3-Phosphate O-Acyltransferase / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D011487:Protein Conformation; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics; D012645:Selenomethionine / Q000378:metabolism; D018724:Spinacia oleracea / Q000201:enzymology*
D018744:DNA, Plant; D005227:Fatty Acids; D010940:Plant Proteins; D011993:Recombinant Fusion Proteins; D012645:Selenomethionine; D005992:Glycerol-3-Phosphate O-Acyltransferase