Biomaterial Database

X-ray crystallographic study of pyridoxal 5'-phosphate-type aspartate aminotransferases from Escherichia coli in open and closed form. 1994

A Okamoto, and T Higuchi, and K Hirotsu, and S Kuramitsu, and H Kagamiyama

Department of Chemistry, Faculty of Science, Osaka City University.

We determined the three-dimensional structures of aspartate aminotransferase (AspAT) from Escherichia coli and its complex with inhibitor (2-methyl-L-aspartate) at 1.8A resolution. This enzyme reversibly catalyzes the transamination reaction and is a dimer of two identical subunits. Each subunit has 396 amino acid residues and one pyridoxal 5'-phosphate as a cofactor, and is divided into two domains, one large and the other small. Upon binding of the inhibitor, the small domain rotates by 5 degrees toward the large domain to close the active site. This domain movement is caused mainly by small but important main-chain conformational changes in the residues located over the domain interface of the small domain. In chicken mitochondrial AspAT, the domain movement was larger, with a rotational angle of 13 degrees. By comparison of these two structures, the difference in the rotational angles was found to be caused by the larger opening of the domain in the open form of chicken mitochondrial AspAT. Although the overall structures of these two enzymes were almost identical, the surface area of the domain interface in the E. coli enzyme was larger than that in mitochondrial AspAT, suggesting that the structure of the domain interface is responsible for the degree of movement of the small domain.

UI	MeSH Term	Description	Entries
D008958	Models, Molecular	Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.	Molecular Models,Model, Molecular,Molecular Model
D004926	Escherichia coli	A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.	Alkalescens-Dispar Group,Bacillus coli,Bacterium coli,Bacterium coli commune,Diffusely Adherent Escherichia coli,E coli,EAggEC,Enteroaggregative Escherichia coli,Enterococcus coli,Diffusely Adherent E. coli,Enteroaggregative E. coli,Enteroinvasive E. coli,Enteroinvasive Escherichia coli
D006860	Hydrogen Bonding	A low-energy attractive force between hydrogen and another element. It plays a major role in determining the properties of water, proteins, and other compounds.	Hydrogen Bonds,Bond, Hydrogen,Hydrogen Bond
D001219	Aspartate Aminotransferases	Enzymes of the transferase class that catalyze the conversion of L-aspartate and 2-ketoglutarate to oxaloacetate and L-glutamate. EC 2.6.1.1.	Aspartate Aminotransferase,Aspartate Transaminase,Glutamic-Oxaloacetic Transaminase,SGOT,Aspartate Apoaminotransferase,Glutamate-Aspartate Transaminase,L-Aspartate-2-Oxoglutarate Aminotransferase,Serum Glutamic-Oxaloacetic Transaminase,Aminotransferase, Aspartate,Aminotransferase, L-Aspartate-2-Oxoglutarate,Aminotransferases, Aspartate,Apoaminotransferase, Aspartate,Glutamate Aspartate Transaminase,Glutamic Oxaloacetic Transaminase,Glutamic-Oxaloacetic Transaminase, Serum,L Aspartate 2 Oxoglutarate Aminotransferase,Serum Glutamic Oxaloacetic Transaminase,Transaminase, Aspartate,Transaminase, Glutamate-Aspartate,Transaminase, Glutamic-Oxaloacetic,Transaminase, Serum Glutamic-Oxaloacetic
D017434	Protein Structure, Tertiary	The level of protein structure in which combinations of secondary protein structures (ALPHA HELICES; BETA SHEETS; loop regions, and AMINO ACID MOTIFS) pack together to form folded shapes. Disulfide bridges between cysteines in two different parts of the polypeptide chain along with other interactions between the chains play a role in the formation and stabilization of tertiary structure.	Tertiary Protein Structure,Protein Structures, Tertiary,Tertiary Protein Structures
D018360	Crystallography, X-Ray	The study of crystal structure using X-RAY DIFFRACTION techniques. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)	X-Ray Crystallography,Crystallography, X Ray,Crystallography, Xray,X Ray Crystallography,Xray Crystallography,Crystallographies, X Ray,X Ray Crystallographies