FIG. 1.

Proposed degradation pathway for DDVA in S. paucimobilis SYK-6. DDVA is transformed to 5CVA and is estimated to be decarboxylated to vanillate on the basis of results described in this study. Vanillate is converted to PCA by a specific O-demethylase and is further degraded through the PCA 4,5-cleavage pathway. Compound abbreviations: CHMS, 4-carboxy-2-hydroxymuconate-6-semialdehyde; PDC, 2-pyrone-4,6-dicarboxylate; OMA, 4-oxalomesaconate; CHA, 4-carboxy-4-hydroxy-2-oxoadipate. The following genes were used: ligX, encoding a component of DDVA O-demethylase; ligZ, encoding OH-DDVA meta-cleavage oxygenase; ligY, encoding OH-DDVA meta-cleavage compound hydrolase; ligW, encoding 5CVA decarboxylase; ligH, encoding a protein involved in the O-demethylation of vanillate and syringate; ligAB, encoding small and large subunits of PCA 4,5-dioxygenase; ligC, encoding CHMS dehydrogenase; ligI, encoding PDC hydrolase; ligJ, encoding OMA hydratase; ligK, encoding CHA aldolase.