The peroxins Pex19 and Pex3 play an indispensable role in peroxisomal membrane protein
(PMP) biogenesis, peroxisome division, and inheritance. Pex19 plays multiple roles in these
processes, but how these functions relate to the structural organization of the Pex19
domains is unresolved. To this end, using deletion mutants, we mapped the Pex19 regions
required for peroxisome biogenesis in the yeast Pichia pastoris. Surprisingly, import-
competent peroxisomes still formed when Pex19 domains previously believed to be …