Three-dimensional solution structure of plastocyanin from the green alga Scenedesmus obliquus

• Published in: Science (American Association for the Advancement of Science) 1988-04, Vol.240 (4850), p.314-317
• Main Authors: Moore, J.M, Case, D.A, Chazin, W.J, Gippert, G.P, Havel, T.F, Powls, R, Wright, P.E
• Format: Article
• Language: English
• Subjects: ALGAE; ALGUE; Atoms; Binding sites; Biochemistry; Biological and medical sciences; Botany; Calorimetry; Chlorophyta - metabolism; Crystal structure; Electron transfer; Electron transport; ESPECTROSCOPIA RMN; Freshwater; Fundamental and applied biological sciences. Psychology; Geometry; Green algae; Ligands; Magnetic Resonance Spectroscopy - methods; Models, Molecular; Molecular biophysics; Molecular dynamics; Molecular structure; NMR SPECTROSCOPY; Nuclear magnetic resonance; Nuclear magnetic resonance spectroscopy; PIGMENT; PIGMENTOS; PIGMENTS; Plant Proteins; Plastocyanin; Protein Conformation; Scenedesmus obliquus; SPECTROSCOPIE RMN; Structure in molecular biology; Tridimensional structure
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.3353725

The solution conformation of plastocyanin from the green alga Scenedesmus obliquus has been determined from distance and dihedral angle constraints derived by nuclear magnetic resonance (NMR) spectroscopy. Structures were generated with distance geometry and restrained molecular dynamics calculations. A novel molecular replacement method was also used with the same NMR constraints to generate solution structures of S. obliquus plastocyanin from the x-ray structure of the homologous poplar protein. Scenedesmus obliquus plastocyanin in solution adopts a $\beta $-barrel structure. The backbone conformation is well defined and is similar overall to that of poplar plastocyanin in the crystalline state. The distinctive acidic region of the higher plant plastocyanins, which functions as a binding site for electron transfer proteins and inorganic complexes, differs in both shape and charge in S. obliquus plastocyanin.