The essential tyrosine of the internalization signal in lysosomal acid phosphatase is part of a beta turn.
For rapid endocytosis lysosomal acid phosphatase requires a Tyr-containing signal in its cytoplasmic domain, as do cell surface receptors mediating endocytosis and clustering in coated pits. To determine the structure of the internalization signal an 18 amino acid peptide representing the cytoplasmic tail of lysosomal acid phosphatase was analyzed by two-dimensional nuclear magnetic resonance spectroscopy. Part of the peptide, 5-PPGY-8, forms a well-ordered beta turn of type I in solution. Our result and data on the structure of the endocytosis signal of the low density lipoprotein receptor reported by Bansal and Gierasch in the accompanying paper represent experimental determinations of the three-dimensional structure of protein transport signals and suggest that the essential aromatic amino acid of internalization signals is recognized by a putative cytoplasmic receptor in the structural context of a tight turn.
Eberle
W
W
European Molecular Biology Laboratory, Heidelberg, Federal Republic of Germany.
Sander
C
C
Klaus
W
W
Schmidt
B
B
von Figura
K
K
Peters
C
C
D000135:Acid Phosphatase / Q000737:chemistry*; D000595:Amino Acid Sequence; D003196:Computer Graphics; D003593:Cytoplasm / Q000648:ultrastructure; D004705:Endocytosis; D066298:In Vitro Techniques; D008247:Lysosomes / Q000201:enzymology; D009682:Magnetic Resonance Spectroscopy; D008562:Membrane Glycoproteins / Q000378:metabolism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010455:Peptides / Q000138:chemical synthesis / Q000737:chemistry; D011487:Protein Conformation; D014443:Tyrosine / Q000737:chemistry
D008562:Membrane Glycoproteins; D010455:Peptides; D014443:Tyrosine; D000135:Acid Phosphatase