| 3GK7: reference: Crystal structure of 4-hydroxybutyrate CoA-transferase from Clostridium aminobutyricum., Macieira S, Zhang J, Velarde M, Buckel W, Messerschmidt A, Biol Chem. 2009 Dec;390(12):1251-63. PMID: 19804364 |
This OCA 
Structure page
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(documentation).