title: Structure of the fibre-forming protein pilin at 2.6 A resolution.
abstract: The crystallographic structure of Neisseria gonorrhoeae pilin, which assembles into the multifunctional pilus adhesion and virulence factor, reveals an alpha-beta roll fold with a striking 85 A alpha-helical spine and an O-linked disaccharide. Key residues stabilize interactions that allow sequence hypervariability, responsible for pilin's celebrated antigenic variation, within disulphide region beta-strands and connections. Pilin surface shape, hydrophobicity and sequence variation constrain pilus assembly to the packing of flat subunit faces against alpha 1 helices. Helical fibre assembly is postulated to form a core of coiled alpha 1 helices banded by beta-sheet, leaving carbohydrate and hypervariable sequence regions exposed to solvent.
mesh_terms: D000595:Amino Acid Sequence; D001425:Bacterial Outer Membrane Proteins / Q000737:chemistry*; D002240:Carbohydrate Sequence; D003198:Computer Simulation; D018360:Crystallography, X-Ray; D004187:Disaccharides / Q000737:chemistry; D036781:Fimbriae Proteins; D010861:Fimbriae, Bacterial / Q000737:chemistry*; D008969:Molecular Sequence Data; D009344:Neisseria gonorrhoeae / Q000737:chemistry*; D011487:Protein Conformation; D017510:Protein Folding; D017433:Protein Structure, Secondary; D013499:Surface Properties
chemical_list: D001425:Bacterial Outer Membrane Proteins; D004187:Disaccharides; D036781:Fimbriae Proteins