Substrate Selectivity of Glycerol-3-phosphate Acyl Transferase in Rice  

作　　者：Su-Qin Zhu Hua Zhao Rong Zhou Ben-Hua Ji Xiao-Yan Dan 

机构地区：[1]School of Life Sciences, Nantong University, Nantong 226007, China

出　　处：《Journal of Integrative Plant Biology》2009年第11期1040-1049,共10页植物学报（英文版）

基　　金：Supported by the National Natural Science Foundation of China (30270794);the Jiangsu Provincial Science Foundation of China (BK2007063 and BK2005041);the Natural Science Foundation of the Education Bureau of Jiangsu Province (06KJB180087 and 04KJB210107)

摘　　要：Substrate selectivity of glycerol-3-phosphate acyltransferase （EC 2. 3. 1. 15） of rice （Oryza sativa L.） was explored in a comparative study of acyltransferases from seven plant species. In vitro labeling of acyl carrier protein （ACP） with ^14C or 3H showed that acyltransferase from chill-sensitive plants, such as rice that uses either oleic （18：1） or palmitic acid （16：0） as acyl donor at comparable rates, displays lower selectivity than the enzyme from chill-resistant plants, such as spinach, which preferentially uses oleic acid （18：1） rather than palmitic acid （16：0） as an acyl donor. This may be a result of the size and character of the substrate-binding pocket of acyltransferase. Homology modeling and protein structure-based sequence alignment of acyltransferases revealed that proteins from either chill-sensitive or chill-tolerant plants shared a highly conserved domain containing the proposed substrate-binding pocket. However, the aligned residues surrounding the substrate-binding pocket are highly heterogeneous and may have an influence mainly on the size of the substrate binding pockets of acyltransferases. The substrate selectivity of acyltransferase of rice can be improved by enlarging the substrate-binding pocket using molecular biological methods.Substrate selectivity of glycerol-3-phosphate acyltransferase （EC 2. 3. 1. 15） of rice （Oryza sativa L.） was explored in a comparative study of acyltransferases from seven plant species. In vitro labeling of acyl carrier protein （ACP） with ^14C or 3H showed that acyltransferase from chill-sensitive plants, such as rice that uses either oleic （18：1） or palmitic acid （16：0） as acyl donor at comparable rates, displays lower selectivity than the enzyme from chill-resistant plants, such as spinach, which preferentially uses oleic acid （18：1） rather than palmitic acid （16：0） as an acyl donor. This may be a result of the size and character of the substrate-binding pocket of acyltransferase. Homology modeling and protein structure-based sequence alignment of acyltransferases revealed that proteins from either chill-sensitive or chill-tolerant plants shared a highly conserved domain containing the proposed substrate-binding pocket. However, the aligned residues surrounding the substrate-binding pocket are highly heterogeneous and may have an influence mainly on the size of the substrate binding pockets of acyltransferases. The substrate selectivity of acyltransferase of rice can be improved by enlarging the substrate-binding pocket using molecular biological methods.

关 键 词：glycerol-3-phosphate acyt transferase homology modeling RICE substrate selectivity. 

分 类 号：TQ464.8[化学工程—制药化工] O623.12[理学—有机化学]