Biomaterial Database

Cooperative binding of zinc to an aminoacyl-tRNA synthetase. 1994

M X Wu, and S J Filley, and K A Hill

Department of Biochemistry, Loma Linda University School of Medicine, California 92350.

Zinc binds to tetrameric alanyl-tRNA synthetase from Escherichia coli with a stoichiometry of one g-atom of zinc per enzyme subunit. The nature of this metal-protein interaction is investigated here through a series of equilibrium dialysis and intrinsic fluorescence experiments. The dialysis data show that zinc binds to this synthetase in a cooperative manner, with half-maximal zinc binding at 0.97 microM free zinc and a Hill coefficient of 1.9. The cooperative feature is also observed in the zinc-induced quenching of the protein intrinsic fluorescence, indicating that zinc binding induces a conformational change. This is the first report of cooperative binding of zinc to an aminoacyl-tRNA synthetase, and the data provide a rationale for the oligomeric structure of the synthetase specific for alanine.

UI	MeSH Term	Description	Entries
D008667	Metalloproteins	Proteins that have one or more tightly bound metal ions forming part of their structure. (Dorland, 28th ed)	Metalloprotein
D011485	Protein Binding	The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.	Plasma Protein Binding Capacity,Binding, Protein
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
D000412	Alanine-tRNA Ligase	An enzyme that activates alanine with its specific transfer RNA. EC 6.1.1.7.	Alanyl T RNA Synthetase,Ala-tRNA Ligase,Alanyl-tRNA Synthetase,Ala tRNA Ligase,Alanine tRNA Ligase,Alanyl tRNA Synthetase,Ligase, Ala-tRNA,Ligase, Alanine-tRNA,Synthetase, Alanyl-tRNA
D001426	Bacterial Proteins	Proteins found in any species of bacterium.	Bacterial Gene Products,Bacterial Gene Proteins,Gene Products, Bacterial,Bacterial Gene Product,Bacterial Gene Protein,Bacterial Protein,Gene Product, Bacterial,Gene Protein, Bacterial,Gene Proteins, Bacterial,Protein, Bacterial,Proteins, Bacterial
D013050	Spectrometry, Fluorescence	Measurement of the intensity and quality of fluorescence.	Fluorescence Spectrophotometry,Fluorescence Spectroscopy,Spectrofluorometry,Fluorescence Spectrometry,Spectrophotometry, Fluorescence,Spectroscopy, Fluorescence
D015032	Zinc	A metallic element of atomic number 30 and atomic weight 65.38. It is a necessary trace element in the diet, forming an essential part of many enzymes, and playing an important role in protein synthesis and in cell division. Zinc deficiency is associated with ANEMIA, short stature, HYPOGONADISM, impaired WOUND HEALING, and geophagia. It is known by the symbol Zn.