Structural basis for competitive interactions of Pex14 with the import receptors Pex5 and Pex19.
Protein import into peroxisomes depends on a complex and dynamic network of protein-protein interactions. Pex14 is a central component of the peroxisomal import machinery and binds the soluble receptors Pex5 and Pex19, which have important function in the assembly of peroxisome matrix and membrane, respectively. We show that the N-terminal domain of Pex14, Pex14(N), adopts a three-helical fold. Pex5 and Pex19 ligand helices bind competitively to the same surface in Pex14(N) albeit with opposite directionality. The molecular recognition involves conserved aromatic side chains in the Pex5 WxxxF/Y motif and a newly identified F/YFxxxF sequence in Pex19. The Pex14-Pex5 complex structure reveals molecular details for a critical interaction in docking Pex5 to the peroxisomal membrane. We show that mutations of Pex14 residues located in the Pex5/Pex19 binding region disrupt Pex5 and/or Pex19 binding in vitro. The corresponding full-length Pex14 variants are impaired in peroxisomal membrane localisation in vivo, showing that the molecular interactions mediated by the N-terminal domain modulate peroxisomal targeting of Pex14.
Neufeld
Christian
C
EMBL Heidelberg, Heidelberg, Germany.
Filipp
Fabian V
FV
Simon
Bernd
B
Neuhaus
Alexander
A
Schüller
Nicole
N
David
Christine
C
Kooshapur
Hamed
H
Madl
Tobias
T
Erdmann
Ralf
R
Schliebs
Wolfgang
W
Wilmanns
Matthias
M
Sattler
Michael
M
D000595:Amino Acid Sequence; D001665:Binding Sites; D001667:Binding, Competitive; D002460:Cell Line; D004252:DNA Mutational Analysis; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008565:Membrane Proteins / Q000737:chemistry* / Q000378:metabolism*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D010455:Peptides / Q000737:chemistry / Q000378:metabolism; D000074435:Peroxisome-Targeting Signal 1 Receptor; D011485:Protein Binding; D017433:Protein Structure, Secondary; D021381:Protein Transport; D018160:Receptors, Cytoplasmic and Nuclear / Q000737:chemistry* / Q000378:metabolism*; D012097:Repressor Proteins / Q000737:chemistry* / Q000378:metabolism*; D012996:Solutions; D055672:Static Electricity; D013329:Structure-Activity Relationship
D008565:Membrane Proteins; C455539:PEX14 protein, human; C000614264:PEX5 protein, human; D010455:Peptides; D000074435:Peroxisome-Targeting Signal 1 Receptor; D018160:Receptors, Cytoplasmic and Nuclear; D012097:Repressor Proteins; D012996:Solutions; C087343:PEX19 protein, human