title: Association between the intrinsically disordered protein PEX19 and PEX3.
abstract: In peroxisomes, peroxins (PEXs) 3 and 19 are the principal protein components of the machinery required for early peroxisomal biogenesis. For further insight into the interaction of PEX3 and PEX19, we used hydrogen exchange mass spectrometry to monitor conformational changes during complex formation between PEX3 and PEX19 in vitro. Our data showed that PEX19 remained highly flexible during interaction with PEX3. However, we could detect three changes, one each in the N-and C-terminus along with a small stretch in the middle of PEX19 (F64-L74) which became shielded from hydrogen exchange when interacting with PEX3. PEX3 became more protected from hydrogen exchange in the binding groove for PEX19 with only small changes elsewhere. Most likely the N-terminus of PEX19 initiates the binding to PEX3, and then subtle conformational changes in PEX3 affect the surface of the PEX3 molecule. PEX19 in turn, is stabilized by folding of a short helix and its C-terminal folding core permitting PEX19 to bind to PEX3 with higher affinity than just the N-terminal interaction allows. Thus within the cell, PEX3 is stabilized by PEX19 preventing PEX3 aggregation.
authors: Institute of Biotechnology, University of Helsinki, Helsinki, Finland.
authors: Katarina
authors: K
authors: Hattula
authors: Institute of Biotechnology, University of Helsinki, Helsinki, Finland.
authors: Daniel
authors: D
authors: Hirschberg
authors: Institute of Biotechnology, University of Helsinki, Helsinki, Finland.
authors: Nisse
authors: N
authors: Kalkkinen
authors: Institute of Biotechnology, University of Helsinki, Helsinki, Finland.
authors: Sarah J
authors: SJ
authors: Butcher
authors: Institute of Biotechnology, University of Helsinki, Helsinki, Finland.
authors: Ari
authors: A
authors: Ora
mesh_terms: D000595:Amino Acid Sequence; D006801:Humans; D008074:Lipoproteins / Q000096:biosynthesis / Q000737:chemistry* / Q000648:ultrastructure; D008565:Membrane Proteins / Q000096:biosynthesis / Q000737:chemistry* / Q000648:ultrastructure; D046912:Multiprotein Complexes / Q000737:chemistry / Q000648:ultrastructure; D000074401:Peroxins; D020675:Peroxisomes / Q000737:chemistry* / Q000235:genetics; D011487:Protein Conformation; D017510:Protein Folding; D060066:Protein Interaction Maps / Q000235:genetics*
chemical_list: D008074:Lipoproteins; D008565:Membrane Proteins; D046912:Multiprotein Complexes; D000074401:Peroxins; C113138:Pex3 protein, human; C087343:PEX19 protein, human