1iuq
From Proteopedia
The 1.55 A Crystal Structure of Glycerol-3-Phosphate Acyltransferase
Structural highlights
FunctionGPAT2_CUCMO Esterifies the acyl-group from acyl-acyl carrier proteins (acyl-ACPs) to the sn-1 position of glycerol-3-phosphate (Ref.3). The physiological acyl donors in chloroplasts are acyl-ACPs, but acyl-CoAs are used as artificial donor for in vitro reactions (Probable). The enzyme from chilling-resistant plants discriminates against non-fluid palmitic acid and selects oleic acid whereas the enzyme from sensitive plants accepts both fatty acids (Ref.3). Squash is chilling-sensitive (Probable). Does not seem to discriminate between the acyl-ACP thioesters 18:1-ACP, 18:0-ACP and 16:0-ACP (Ref.3). Exhibits higher selectivity for 16:0-CoA than 18:1-CoA in vitro (PubMed:9016814, PubMed:14684887).[1] [2] [3] [4] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedStromal 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. Substrate recognition and selectivity of plant glycerol-3-phosphate acyltransferases (GPATs) from Cucurbita moscata and Spinacea oleracea.,Tamada T, Feese MD, Ferri SR, Kato Y, Yajima R, Toguri T, Kuroki R Acta Crystallogr D Biol Crystallogr. 2004 Jan;60(Pt 1):13-21. Epub 2003, Dec 18. PMID:14684887[5] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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