Assembly line termination in cylindrocyclophane biosynthesis: discovery of an editing type II thioesterase domain in a type I polyketide synthase.

ABSTRACT: The termination step is an important source of structural diversity in polyketide biosynthesis. Most type I polyketide synthase (PKS) assembly lines are terminated by a thioesterase (TE) domain located at the C-terminus of the final module, while other PKS assembly lines lack a terminal TE domain and are instead terminated by a separate enzyme in trans. In cylindrocyclophane biosynthesis, the type I modular PKS assembly line is terminated by a freestanding type III PKS (CylI). Unexpectedly, the final module of the type I PKS (CylH) also possesses a C-terminal TE domain. Unlike typical type I PKSs, the CylH TE domain does not influence assembly line termination by CylI in vitro. Instead, this domain phylogenetically resembles a type II TE and possesses activity consistent with

SUBMITTER: Nakamura H 

PROVIDER: S-EPMC5707447 | biostudies-literature | 2015 Jul

REPOSITORIES: biostudies-literature