title: Crystal structure of vitelline membrane outer layer protein I (VMO-I): a folding motif with homologous Greek key structures related by an internal three-fold symmetry.
abstract: The crystal structure of vitelline membrane outer layer protein I (VMO-I), which is isolated from the vitelline membrane outer layer of hen's eggs, has been determined by the multiple isomorphous replacement method and refined to an R-factor of 18.8% at 2.2 A resolution. The main chain folds into an unusual structure that consists of three beta-sheets forming Greek key motifs, which are related by an internal pseudo three-fold symmetry. The internal portion surrounded by these three beta-sheets is filled with hydrophobic side chains. This conformational feature coincides with three internal repeats in the sequence. Although a similar fold exists in the second domain of delta-endotoxin, there are significant structural differences between the two proteins, with the three-fold symmetry being most regular in VMO-I.
authors.affiliation: Protein Engineering Research Institute, Osaka, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Shimizu
authors.forename: D G
authors.initials: DG
authors.lastname: Vassylyev
authors.forename: S
authors.initials: S
authors.lastname: Kido
authors.forename: Y
authors.initials: Y
authors.lastname: Doi
authors.forename: K
authors.initials: K
authors.lastname: Morikawa
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002645:Chickens; D002942:Circular Dichroism; D018360:Crystallography, X-Ray; D004527:Egg Proteins / Q000737:chemistry* / Q000302:isolation & purification; D005260:Female; D008958:Models, Molecular; D008969:Molecular Sequence Data; D017510:Protein Folding; D017433:Protein Structure, Secondary; D014817:Vitelline Membrane / Q000737:chemistry*
chemical_list: D004527:Egg Proteins; C035651:vitelline membrane proteins