Mutation on N-terminus of polyhydroxybutyrate synthase of Ralstonia eutropha enhanced PHB accumulation.
Polyhydroxyalkanoate (PHA) synthase is the central enzyme involved in the biosynthesis of PHA, a family of bacterial biodegradable polyesters. Due to its high variability, the N-terminal fragment of this enzyme was previously considered as unnecessary for a functionally active enzyme. In this study, polyhydroxybutyrate synthase from Ralstonia eutropha (PhbC(Re)) with a deletion on N-terminal 88 amino acid residues showed a significant reduced activity, as reflected by only 1.5% PHB accumulation compared with the wild type which produced 58.4% PHB of the cell dry weight. Whilst several site-specific mutagenesis results revealed the amphiphilic alpha-helix assembled by the amino acid region, D70-E88 played an important role in both maintaining the PHB synthase activity and regulating molecular weight and polydispersity of accumulated PHB homopolymer.
Zheng
Zhong
Z
MOE Laboratory of Protein Science, Department of Biological Sciences and Biotechnology, Tsinghua University, Beijing, 100084, China.
Li
Ming
M
Xue
Xiao-Jing
XJ
Tian
Hong-Lei
HL
Li
Zhi
Z
Chen
Guo-Qiang
GQ