title: Hansenula polymorpha Pex20p is an oligomer that binds the peroxisomal targeting signal 2 (PTS2).
abstract: We have cloned and characterized the Hansenula polymorpha PEX20 gene. The HpPEX20 gene encodes a protein of 309 amino acids (HpPex20p) with a calculated molecular mass of approximately 35 kDa. In cells of an HpPEX20 disruption strain, PTS2 proteins were mislocalized to the cytosol, whereas PTS1 matrix protein import proceeded normally. Also, the PTS2 proteins amine oxidase and thiolase were normally assembled and active in these cells, suggesting HpPex20p is not involved in oligomerization/activation of these proteins. Localization studies revealed that HpPex20p is predominantly associated with peroxisomes. Using fluorescence correlation spectroscopy we determined the native molecular mass of purified HpPex20p and binding of a synthetic peptide containing a PTS2 sequence. The data revealed that purified HpPex20p forms oligomers, which specifically bind PTS2-containing peptides.
authors.affiliation: Eukaryotic Microbiology, Groningen Biomolecular Sciences and Biotechnology Institute (GBB), University of Groningen, PO Box 14, NL-9750 AA Haren, The Netherlands.
authors.forename: Marleen
authors.initials: M
authors.lastname: Otzen
authors.forename: Dongyuan
authors.initials: D
authors.lastname: Wang
authors.forename: Marcel G J
authors.initials: MG
authors.lastname: Lunenborg
authors.forename: Ida J
authors.initials: IJ
authors.lastname: van der Klei
mesh_terms: D003001:Cloning, Molecular; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008856:Microscopy, Fluorescence; D008970:Molecular Weight; D009841:Oligonucleotides / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000074437:Peroxisomal Targeting Signal 2 Receptor; D010843:Pichia / Q000737:chemistry / Q000166:cytology / Q000235:genetics*; D018160:Receptors, Cytoplasmic and Nuclear / Q000737:chemistry / Q000378:metabolism*; D013997:Time Factors
chemical_list: D005656:Fungal Proteins; D009841:Oligonucleotides; D000074437:Peroxisomal Targeting Signal 2 Receptor; D018160:Receptors, Cytoplasmic and Nuclear