Journal
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
Volume 136, Issue 48, Pages 16792-16799Publisher
AMER CHEMICAL SOC
DOI: 10.1021/ja5064857
Keywords
-
Categories
Funding
- National Institutes of Health [GM100305, GM095970]
- NATIONAL INSTITUTE OF GENERAL MEDICAL SCIENCES [R01GM095970, K12GM068524, R01GM100305] Funding Source: NIH RePORTER
Ask authors/readers for more resources
The mechanistic details of many polyketide synthases (PKSs) remain elusive due to the instability of transient intermediates that are not accessible via conventional methods. Here we report an atom replacement strategy that enables the rapid preparation of polyketone surrogates by selective atom replacement, thereby providing key substrate mimetics for detailed mechanistic evaluations. Polyketone mimetics are positioned on the actinorhodin acyl carrier protein (actACP) to probe the underpinnings of substrate association upon nascent chain elongation and processivity. Protein NMR is used to visualize substrate interaction with the actACP, where a tetraketide substrate is shown not to bind within the protein, while heptaketide and octaketide substrates show strong association between helix II and IV. To examine the later cyclization stages, we extended this strategy to prepare stabilized cyclic intermediates and evaluate their binding by the actACP. Elongated monocyclic mimics show much longer residence time within actACP than shortened analogs. Taken together, these observations suggest ACP-substrate association occurs both before and after ketoreductase action upon the fully elongated polyketone, indicating a key role played by the ACP within PKS timing and processivity. These atom replacement mimetics offer new tools to study protein and substrate interactions and are applicable to a wide variety of PKSs.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available