4BHB:
reference: BIOCHEMICAL AND STRUCTURAL STUDIES ON THE M. TUBERCULOSIS O6-METHYLGUANINE METHYLTRANSFERASE AND MUTATED VARIANTS., Miggiano R, Casazza V, Garavaglia S, Ciaramella M, Perugino G, Rizzi M, Rossi F, J Bacteriol. 2013 Apr 5. PMID: 23564173

This OCA Structure page
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