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Crystal structure of misoprostol bound to the labor inducer prostaglandin E2 receptor

A Publisher Correction to this article was published on 20 December 2018

This article has been updated


Misoprostol is a life-saving drug in many developing countries for women at risk of post-partum hemorrhaging owing to its affordability, stability, ease of administration and clinical efficacy. However, misoprostol lacks receptor and tissue selectivities, and thus its use is accompanied by a number of serious side effects. The development of pharmacological agents combining the advantages of misoprostol with improved selectivity is hindered by the absence of atomic details of misoprostol action in labor induction. Here, we present the 2.5 Å resolution crystal structure of misoprostol free-acid form bound to the myometrium labor-inducing prostaglandin E2 receptor 3 (EP3). The active state structure reveals a completely enclosed binding pocket containing a structured water molecule that coordinates misoprostol's ring structure. Modeling of selective agonists in the EP3 structure reveals rationales for selectivity. These findings will provide the basis for the next generation of uterotonic drugs that will be suitable for administration in low resource settings.

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Fig. 1: Overall structure of EP3 receptor bound to misoprostol-FA.
Fig. 2: Detailed structure of the misoprostol-FA binding pocket and interactions of the ligand with the EP3 receptor.
Fig. 3: The binding pocket of misoprostol-FA in EP3 receptor is totally enclosed.
Fig. 4: Docking of small agonists on the EP3 receptor.
Fig. 5: Modeling of sulprostone and GR-63799 on the EP3 receptor.

Data availability

The misoprostol-FA EP3 receptor complex structure coordinates and structure factors are available via the Protein Data Bank (PDB) accession code 6M9T.

Change history

  • 20 December 2018

    In the version of this article originally published, the present address for Petr Popov was incorrectly listed as ‘Koltech Institute of Science & Technology, Moscow, Russia’. The correct present address is ‘Skolkovo Institute of Science and Technology, Moscow, Russia’. The error has been corrected in the HTML and PDF versions of the paper.


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This research was supported by NIH R35 GM127086 (V.C.), R21 DA042298 (W.L.), R01 GM124152 (W.L.), the STC Program of the National Science Foundation through BioXFEL (No. 1231306) (U.W. and W.L.), the Russian Science Foundation (project no. 16-14-10273), and the GPCR Consortium. M.A. was supported by a Canadian Institute of Health and Research (CIHR) Postdoctoral Fellowship Award. C.G. acknowledges the Panofsky Fellowship from SLAC National Accelerator Laboratory and Stanford University for financial support. P.P. and V.K. acknowledge the Russian Foundation for Basic Research (RFBR No.18-34-00990). Parts of this research were carried out at the LCLS, a National User Facility operated by Stanford University on behalf of the US Department of Energy and is supported by the US Department of Energy, Office of Science, Office of Basic Energy Sciences under contract no. DE-AC0276SF00515, and at the GM/CA CAT of the Argonne Photon Source, Argonne National Laboratory. We thank A. Walker for assistance in manuscript preparation; M. Chu, K. Villiers and C. Hanson for baculovirus expression and mammalian cell culture, and N. Sawyer for helpful suggestions. We are grateful to F. Badeaux and E. Audet-Badeaux for their encouragement and support.

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Authors and Affiliations



M.A. designed the study, crystallized the EP3 receptor, prepared samples for data collection, collected the data for XFEL and synchrotron, and solved and refined the structure. K.L.W. and M.A. performed the binding assays. B.B. performed the signaling assays. B.Z. and V.K. performed ligand docking and selectivity analysis. Y.L. and W.S. performed mass spectrometry. J.V. and D.M. performed molecular biology. P.P. suggested the mutation. C.G. processed the crystallographic XFEL data. A.B. helped with the XFEL data collection. W.L. helped with sample preparation for XFEL data collection. H.H. and U.W. operated the sample injector during XFEL data collection. G.W.H. solved and refined the structure. V.C. supervised XFEL data collection and processing. M.A.H., V.K., and R.C.S. supervised the project. All authors wrote the manuscript.

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Correspondence to Raymond C. Stevens.

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Competing interests

B.B is an employee of Domain Therapeutics NA, a company focused on GPCR drug discovery that sells and licenses the cell signaling kit used in this study. All other authors declare no competing interests.

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Audet, M., White, K.L., Breton, B. et al. Crystal structure of misoprostol bound to the labor inducer prostaglandin E2 receptor. Nat Chem Biol 15, 11–17 (2019).

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