The three-dimensional structure of the cell wall glycoprotein of Chlorogonium elongatum

• Published in: Journal of cell science Vol. 68; no. 1; pp. 271 - 284
• Main Authors: SHAW, P. J, HILLS, G. J
• Format: Journal Article
• Language: English
• Published: Cambridge Company of Biologists 01.06.1984
• Subjects: Analytical, structural and metabolic biochemistry; Biological and medical sciences; Cell Wall - ultrastructure; Chlorogonium elongatum; Chlorophyta - ultrastructure; Fundamental and applied biological sciences. Psychology; Glycoproteins; Microscopy, Electron; Models, Molecular; Optics and Photonics; Protein Conformation; Proteins; Cell structure; Vegetals; Image processing; Algae; Chlorophycophyta; Glycoproteins; Electron microscopy; Cell wall; Thallophyta; Crystalline structure
• ISSN: 0021-9533; 1477-9137
• DOI: 10.1242/jcs.68.1.271

The green alga Chlorogonium elongatum, a member of the Volvocales, possesses a crystalline cell wall composed of hydroxyproline-rich glycoprotein similar to the primary cell wall glycoproteins of higher plants. Electron microscopy and computer image processing have been used to determine the crystal structure of the Chlorogonium cell wall in three dimensions to a resolution of 2.0 nm. The structure is composed of heterologous dimers. Each subunit of the dimer comprises a long, thin spacer domain and a large globular domain, which is the site of the intra- and inter-dimer interactions. There are also sites of intersubunit interactions at the opposite ends of the rod domains. We suggest that the rods are composed predominantly of glycosylated polyproline helix, as has been suggested for higher plant cell wall glycoproteins and has been shown for the cell wall glycoprotein of Chlamydomonas reinhardtii, which is closely related to Chlorogonium.