-!- Involved in biotin biosynthesis in Gram-negative bacteria. -!- The enzyme exhibits carboxylesterase activity, particularly toward substrates with short acyl chains. -!- Even though the enzyme can interact with coenzyme A thioesters, the in vivo role of the enzyme is to hydrolyze the methyl ester of pimeloyl-[acyl carrier protein], terminating the part of the biotin biosynthesis pathway that is catalyzed by the fatty acid elongation enzymes.