SCAN: 1,3-propanediol dehydrogenase from Klebsiella pneumoniae: portrait of a type III alcohol dehydrogenase

Abstract

Alcohol dehydrogenases are a rather old subject. They play a central role in the most ancient business of biotechnology: alcoholic fermentation. As a consequence, they also play an important role in our liver and stomach, providing a line of defense against a potentially dangerous molecule, ethanol. It is therefore not strange that they were a subject of early attention, with the first alcohol dehydrogenase purified and crystallized in 1937. However, there are many different enzymes that interconvert alcohols, aldehydes and ketones.The enzyme 1,3-propanodiol dehydrogenase from Klebsiella pneumoniae is a type III iron-dependent  dehydrogenase, a not so well studied group of enzymes, with very few known structures. In despite of its pathogenicity, this microorganism has several metabolic potentials that could be used in biotechnology applications. K. pneumoniae is able to metabolize glycerol as a sole source of carbon and energy and 1,3-propanediol dehydrogenase is the core of the metabolic pathway for the use of glycerol. The overall arrangement of the enzyme showed a decameric structure, formed by a pentamer of dimers, which is the catalytic form of the enzyme.