2I37:
reference: Crystal structure of a photoactivated deprotonated intermediate of rhodopsin., Salom D, Lodowski DT, Stenkamp RE, Trong IL, Golczak M, Jastrzebska B, Harris T, Ballesteros JA, Palczewski K, Proc Natl Acad Sci U S A. 2006 Oct 31;103(44):16123-8. Epub 2006 Oct 23. PMID: 17060607

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