3LCE:
reference: Cyclobutanone analogues of beta-lactams revisited: insights into conformational requirements for inhibition of serine- and metallo-beta-lactamases., Johnson JW, Gretes M, Goodfellow VJ, Marrone L, Heynen ML, Strynadka NC, Dmitrienko GI, J Am Chem Soc. 2010 Mar 3;132(8):2558-60. PMID: 20141132

This OCA Structure page
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