3.4.21.48 expressed in Escherichia coli DH5-alpha, generation and transformation of protease B-knockout strain of Saccaromyces termed MT8-1/delta-PrB described 683085 3.4.21.48 generation of a yeast strain with PBN1 under control of the GAL promoter and of strains depleted of Pbn1p, transformation of Saccaromyces BJ 5410 with the PBN1 gene to generate the pGAL-HA-PBN1 strain BJ 10242, properties of strain BJ 10242 by processing activities of transient proteins of the endoplasmic reticulum indicated 682540