Dynamic Changes of Intracellular Monomer Levels Regulate Block Sequence of Polyhydroxyalkanoates in Engineered Escherichia coli.
Biomacromolecules
; 19(2): 662-671, 2018 02 12.
Article
em En
| MEDLINE
| ID: mdl-29323923
ABSTRACT
Biological polymer synthetic systems, which utilize no template molecules, normally synthesize random copolymers. We report an exception, a synthesis of block polyhydroxyalkanoates (PHAs) in an engineered Escherichia coli. Using an engineered PHA synthase, block copolymers poly[(R)-2-hydroxybutyrate(2HB)-b-(R)-3-hydroxybutyrate(3HB)] were produced in E. coli. The covalent linkage between P(2HB) and P(3HB) segments was verified with solvent fractionation and microphase separation. Notably, the block sequence was generated under the simultaneous consumption of two monomer precursors, indicating the existence of a rapid monomer switching mechanism during polymerization. Based on in vivo metabolic intermediate analysis and the relevant in vitro enzymatic activities, we propose a model in which the rapid intracellular 3HB-CoA fluctuation during polymer synthesis is a major factor in generating block sequences. The dynamic change of intracellular monomer levels is a novel regulatory principle of monomer sequences of biopolymers.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Escherichia coli
/
Poli-Hidroxialcanoatos
/
Microrganismos Geneticamente Modificados
Tipo de estudo:
Prognostic_studies
Idioma:
En
Ano de publicação:
2018
Tipo de documento:
Article