The filamentous fungus Cochliobolus carbonum produces endo-alpha 1,4-polygalacturonase (endoPG), exo-alpha 1,4-polygalacturonase (exoPG), and pectin methylesterase when grown in culture on pectin. Residual activity in a pgn1 mutant (lacking endoPG) was due to exoPG activity, and the responsible protein has now been purified. After chemical deglycosylation, the molecular mass of the purified pro...