Fig. 2

Illustration of a postulated pathway for acetone degradation in Desulfococcus biacutus with an attributed role of Debia-MDR as 3-hydroxybutanal dehydrogenase. In this hypothetical pathway, acetone would be carbonylated or formylated to a branched-chain aldehyde and then isomerized to linear 3-hydroxybutanal. The 3-hydroxybutanal would be oxidized to acetoacetaldehyde by the enzyme described in this study. Subsequently, acetoacetaldehyde could be converted to acetoacetyl-CoA (see also main text)