A peptide derived from the C-terminal part of a plant cysteine protease folds into a stack of two beta-hairpins, a scaffold present in the emerging family of granulin-like growth factors.
A 35 amino acid residue peptide corresponding to the N-terminal subdomain of the granulin-like repeat from rice oryzain beta was synthesized and regioselectively oxidized to produce a species with a [1-3, 2-4] disulfide-pairing pattern. The resulting peptide was studied in solution using NMR and was shown to adopt the tertiary topology of a stack of two beta-hairpins found in the emerging family of granulin-like growth factors. Because of the longer second beta-hairpin, the overall conformation of the peptide is somewhat more flexible than that of its well-structured carp granulin-1 analog. Except for the cysteine alignment, there is very little sequence homology between granulin-like growth factors from the animal kingdom and the granulin-like repeats at the C-termini of plant cysteine proteases. Therefore, the stack of two beta-hairpins may be a conserved three-dimensional organization of the granulin-like repeats from evolutionary distant sources with a significant role in specific protein-protein interactions.
Tolkatchev
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Montreal Joint Centre for Structural Biology, Biotechnology Research Institute, National Research Council of Canada, Québec.
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D000595:Amino Acid Sequence; D003546:Cysteine Endopeptidases / Q000737:chemistry*; D004220:Disulfides / Q000737:chemistry; D006133:Growth Substances / Q000737:chemistry*; D036341:Intercellular Signaling Peptides and Proteins; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008969:Molecular Sequence Data; D012275:Oryza / Q000201:enzymology; D010084:Oxidation-Reduction; D010446:Peptide Fragments / Q000737:chemistry; D010940:Plant Proteins / Q000737:chemistry; D000077153:Progranulins; D011487:Protein Conformation; D017510:Protein Folding; D014764:Viral Proteins / Q000737:chemistry*
D004220:Disulfides; D006133:Growth Substances; D036341:Intercellular Signaling Peptides and Proteins; D010446:Peptide Fragments; D010940:Plant Proteins; D000077153:Progranulins; D014764:Viral Proteins; D003546:Cysteine Endopeptidases