标题：Incremental truncation of PHA synthases results in altered product specificity
作者：Wang, Qian; Xia, Yongzhen; Chen, Quan; Qi, Qingsheng
作者机构：[Wang, Qian; Xia, Yongzhen; Chen, Quan; Qi, Qingsheng] Shandong Univ, Sch Life Sci, Natl Glycoengn Res Ctr, State Key Lab Microbial Technol, Jinan 250 更多
通讯作者地址：[Qi, QS]Shandong Univ, Sch Life Sci, Natl Glycoengn Res Ctr, State Key Lab Microbial Technol, Jinan 250100, Peoples R China.
来源：ENZYME AND MICROBIAL TECHNOLOGY
关键词：Polyhydroxyalkanoates; PHA synthase; Hybrid; Copolymer; Incremental; truncation; Library
摘要：PHA synthase is the key enzyme involved in the biosynthesis of microbial polymers, polyhydroxyalkanoates (PHA). In this study, we created a hybrid library of PHA synthase gene with different crossover points by an incremental truncation method between the C-terminal fragments of the phaC(cn) (phaC from Cupriavidus necator) and the N-terminal fragments of the phaC1(pa) (phaC from Pseudomonas aeruginosa). As the truncation of the hybrid enzyme increased, the in vivo PHB synthesis ability of the hybrids declined gradually. PHA synthase PhaC(Cn) with a deletion on N-terminal up to 83 amino acid residues showed no synthase activity. While with the removal of up to 270 amino acids from the N-terminus, the activity of the truncated PhaC(Cn), could be complemented by the N-terminus of PhaC1(Pd). Three of the hybrid enzymes W188, W235 and W272 (named by the deleted nucleic acid number) were found to have altered product specificities. (C) 2012 Elsevier Inc. All rights reserved.