Related Experiment Video
Updated: Aug 14, 2026

Production, Crystallization and Structure Determination of C. difficile PPEP-1 via Microseeding and Zinc-SAD
Published on: December 30, 2016
Crystal structure of soybean proglycinin A1aB1b homotrimer
M Adachi1, Y Takenaka, A B Gidamis
1Research Institute for Food Science, Kyoto University, Uji, Kyoto, 611-0011, Japan.
Abstract:
Soybean glycinin is a member of the 11 S globulin family. The crystal structure of proglycinin was determined by X-ray crystallography at 2.8 A resolution with an R-factor of 0.199 and a free R-factor of 0.250. A trimer molecule was found in an asymmetric unit of crystals. The trimer model contains three A1aB1b subunits and comprises 1128 amino acid residues and 34 water molecules. The constituent protomers of the homo-trimeric protein are arranged around a 3-fold symmetry axis with dimensions of 95 Ax95 Ax40 A. The protomer model is composed of five fragments which correspond roughly to conserved regions based on the sequence alignment of various 11 S globulins. The core of the protomer consists of two jelly-roll beta-barrels and two extended helix domains. This structure of proglycinin is similar to those of canavalin and phaseolin belonging to the 7 S globulin family, strongly supporting the hypothesis that both 7 S and 11 S globulins are derived from a common ancestor. The inter and intra-chain disulfide bonds conserved in the 11 S globulin family are clearly observed. It is found that the face with the inter-chain disulfide bond (IE face) contains more hydrophobic residues than that with the intra-chain disulfide bond. This suggests that a mature hexamer is formed by the interaction between the IE faces after processing.
More Related Videos
11:27X-Ray Crystallography to Study the Oligomeric State Transition of the Thermotoga maritima M42 Aminopeptidase TmPep1050
Published on: May 13, 2020
09:31PCR Mutagenesis, Cloning, Expression, Fast Protein Purification Protocols and Crystallization of the Wild Type and Mutant Forms of Tryptophan Synthase
Published on: September 26, 2020
Related Concept Videos
Protein Organization
Protein and Protein Structure
A protein's shape is critical to its function. For example, an enzyme can...
Protein Organization
Globular and Fibrous Proteins
Globular proteins are also known as spheroproteins and typically are approximately round in shape. They contain a mix of amino acid types and contain differing sequences in their primary structures. Globular proteins have many different functions, such as enzymes, cellular messengers, and molecular transporters. These roles often require the proteins to be...
Protein Organization
The primary structure of a protein is its amino acid sequence.
Globular and Fibrous Proteins
Globular proteins are also known as spheroproteins and typically are approximately round in shape. They contain a mix of amino acid types and contain differing sequences in their primary structures. Globular proteins have many different functions, such as enzymes, cellular messengers, and molecular transporters. These roles often require the proteins to be...