2XSS:
reference: Crystal structure of the GAF-B domain from human phosphodiesterase 5., Russwurm M, Schlicker C, Weyand M, Koesling D, Steegborn C, Proteins. 2011 May;79(5):1682-7. doi: 10.1002/prot.22989. Epub 2011 Mar, 21. PMID: 21425347

This OCA Structure page
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