title: Disulfide structure of the leucine-rich repeat C-terminal cap and C-terminal stalk region of Nogo-66 receptor.
abstract: Nogo-66 receptor (NgR1) is a leucine-rich repeat (LRR) protein that forms part of a signaling complex modulating axon regeneration. Previous studies have shown that the entire LRR region of NgR1, including the C-terminal cap of the LRR, LRRCT, is needed for ligand binding, and that the adjacent C-terminal region (CT stalk) of the NgR1 contributes to interaction with its coreceptors. To provide structure-based information for these interactions, we analyzed the disulfide structure of full-length NgR1. Our analysis revealed a novel disulfide structure in the C-terminal region of the NgR1, wherein the two Cys residues, Cys-335 and Cys-336, in the CT stalk are disulfide-linked to Cys-266 and Cys-309 in the LRRCT region: Cys-266 is linked to Cys-335, and Cys-309 to Cys-336. The other two Cys residues, Cys-264 and Cys-287, in the LRRCT region are disulfide-linked to each other. The analysis also showed that Cys-419 and Cys-429, in the CT stalk region, are linked to each other by a disulfide bond. Although published crystal structures of a recombinant fragment of NgR1 had revealed a disulfide linkage between Cys-266 and Cys-309 in the LRRCT region and we verified its presence in the corresponding fragment, this is artificially caused by the truncation of the protein, since this linkage was not detected in intact NgR1 or a slightly larger fragment containing Cys-335 and Cys-336. A structural model of the LRRCT with extended residues 311-344 from the CT stalk region is proposed, and its function in coreceptor binding is discussed.
authors.affiliation: Biogenidec, Inc., 14 Cambridge Center, Cambridge, Massachusetts 02142, USA. dingyi.wen@biogenidec.com
authors.forename: Dingyi
authors.initials: D
authors.lastname: Wen
authors.forename: Craig P
authors.initials: CP
authors.lastname: Wildes
authors.forename: Laura
authors.initials: L
authors.lastname: Silvian
authors.forename: Lee
authors.initials: L
authors.lastname: Walus
authors.forename: Sha
authors.initials: S
authors.lastname: Mi
authors.forename: Daniel H S
authors.initials: DH
authors.lastname: Lee
authors.forename: Werner
authors.initials: W
authors.lastname: Meier
authors.forename: R Blake
authors.initials: RB
authors.lastname: Pepinsky
mesh_terms: D000478:Alkylation; D000595:Amino Acid Sequence; D002851:Chromatography, High Pressure Liquid; D004220:Disulfides / Q000737:chemistry*; D004591:Electrophoresis, Polyacrylamide Gel; D058851:GPI-Linked Proteins; D006801:Humans; D007930:Leucine / Q000737:chemistry*; D013058:Mass Spectrometry; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009185:Myelin Proteins; D000070816:Nogo Receptor 1; D010449:Peptide Mapping; D011487:Protein Conformation; D011956:Receptors, Cell Surface; D011994:Recombinant Proteins / Q000737:chemistry; D020449:Repetitive Sequences, Amino Acid; D014357:Trypsin / Q000737:chemistry
chemical_list: D004220:Disulfides; D058851:GPI-Linked Proteins; D009185:Myelin Proteins; D000070816:Nogo Receptor 1; C486580:RTN4R protein, human; D011956:Receptors, Cell Surface; D011994:Recombinant Proteins; D014357:Trypsin; D007930:Leucine