Molecular basis of an agarose metabolic pathway acquired by a human intestinal symbiont.

In red algae, the most abundant principal cell wall polysaccharides are mixed galactan agars, of which agarose is a common component. While bioconversion of agarose is predominantly catalyzed by bacteria that live in the oceans, agarases have been discovered in microorganisms that inhabit diverse terrestrial ecosystems, including human intestines. Here we comprehensively define the structure-function relationship of the agarolytic pathway from the human intestinal bacterium Bacteroides uniformis (Bu) NP1.