Oxygenase component of a two-component system involved in the degradation of tertiary alcohols such as tert-butyl alcohol (TBA) and tert-amyl alcohol (TAA). In the presence of TBA, catalyzes the hydroxylation of TBA to 2-methylpropane-1,2-diol. In the presence of TAA, functions as a desaturase, enabling the degradation of TAA and resulting in the formation of the hemiterpene 3-hydroxy-3-methylbut-1-ene. The specificity of the catalysis depends strongly on the molecule structure of the substrate, allowing either hydroxylation or desaturation reactions (PubMed:22194447). Also catalyzes the desaturation of the tertiary alcohol 3-methyl-3-pentanol (a C6 homolog of TBA and TAA) to 3-methyl-1-penten-3-ol, with lower efficiency (PubMed:22194447). In addition, can transform some secondary alcohols, including the hydroxylation of 2-propanol to 1,2-propanediol, and the desaturation of 2-butanol, 3-methyl-2-butanol and 3-pentanol (PubMed:22752178). H(+) + NADPH + O2 + tert-butanol = 2-methylpropane-1,2-diol + H2O + NADP(+) 2-methylbutan-2-ol + H(+) + NADPH + O2 = 3-hydroxy-3-methylbut-1-ene + 2 H2O + NADP(+) Binds 1 [2Fe-2S] cluster per subunit. This two-component enzyme is composed of an oxygenase (MdpJ) and a reductase (MdpK). Induced in the presence of tert-butyl alcohol (TBA). Mutants are not able to grow on the tertiary alcohols TBA and TAA. Shows a biotechnological potential for the synthesis of enantiopure short-chain diols and unsaturated alcohols from secondary alcoholic precursors. Belongs to the bacterial ring-hydroxylating dioxygenase alpha subunit family.