BioChem - DOS

Comprehensive in Vitro Analysis of Acyltransferase Domain Exchanges in Modular Polyketide Synthases and Its Application for Short-Chain Ketone Production

ACS Synthetic biology

Yuzawa, Satoshi; Deng, Kai; Wang, George; Baidoo, Edward E. K.; Northen, Trent R.; Adams, Paul D.; Katz, Leonard; Keasling, Jay D.

<P>Type I modular polyketide synthases (PKSs) are polymerases that utilize acyl-CoAs as substrates. Each polyketide elongation reaction is catalyzed by a set of protein domains called a module. Each module usually contains an acyltransferase (AT) domain, which determines the specific acyl-CoA incorporated into each condensation reaction. Although a successful exchange of individual AT domains can lead to the biosynthesis of a large variety of novel compounds, hybrid PKS modules often show significantly decreased activities. Using monomodular PKSs as models, we have systematically analyzed the segments of AT domains and associated linkers in AT exchanges <I>in vitro</I> and have identified the boundaries within a module that can be used to exchange AT domains while maintaining protein stability and enzyme activity. Importantly, the optimized domain boundary is highly conserved, which facilitates AT domain replacements in most type I PKS modules. To further demonstrate the utility of the optimized AT domain boundary, we have constructed hybrid PKSs to produce industrially important short-chain ketones. Our <I>in vitro</I> and <I>in vivo</I> analysis demonstrated production of predicted ketones without significant loss of activities of the hybrid enzymes. These results greatly enhance the mechanistic understanding of PKS modules and prove the benefit of using engineered PKSs as a synthetic biology tool for chemical production.</P><P><B>Graphic Abstract</B><BR><IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/asbcd6/2017/asbcd6.2017.6.issue-1/acssynbio.6b00176/production/images/medium/sb-2016-00176f_0006.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/sb6b00176'>ACS Electronic Supporting Info</A></P>

2017

American Chemical Society

2161-5063

6

1

pp.139-147

10.1021/acssynbio.6b00176.s001

http://click.ndsl.kr/servlet/OpenAPIDetailView?keyValue=05787966&target=NART&cn=NART77246980

https://doi.org/10.1021/acssynbio.6b00176.s001

Type I modular polyketide synthase; acyltransferase domain; substrate specificity; protein engineering; synthetic biology tool