A - ligand interactions : ( I ) magnesium binding sites in yeast tRNA
نویسندگان
چکیده
X-ray crystallographic studies indicate that there are at least four site-specifically bound hydrated Mg 2 + ions, [Mg(H20)n] , in yeast tRNA. The size and the octahedral coordination geometry, rather than the charge, of [Mg(H2O)n] 2+ appear to be the primary reasons for the specificity of magnesium ions in site-binding and in the stabilization of the tertiary structure of tRNA.
منابع مشابه
RNA-ligant interactions. (I) Magnesium binding sites in yeast tRNAPhe.
X-ray crystallagraphic studies studies indicate that there are at least four site-specifically bound hydrated Mg2+ ions, [Mg(H2O)n]2+, in yeast tRNAPhe. The size and the octahedral coordination geometry, rather than the charge, of [Mg(H2O)N]2+ appear to be the primary reasons for the specificity of magnesium ions in site-binding and in the stabilization of the tertiary structure of tRNA.
متن کاملOutersphere and innersphere coordinated metal ions in an aminoacyl-tRNA synthetase ribozyme.
Metal ions are essential cofactors for various ribozymes. Here we dissect the roles of metal ions in an aminoacyl-tRNA synthetase-like ribozyme (ARS ribozyme), which was evolved in vitro. This ribozyme can charge phenylalanine on tRNA in cis, where it is covalently attached to the 5'-end of tRNA (i.e. a form of precursor tRNA), as well as in trans, where it can act as a catalyst. The presence o...
متن کاملEnhanced Interaction between Pseudokinase and Kinase Domains in Gcn2 stimulates eIF2α Phosphorylation in Starved Cells
The stress-activated protein kinase Gcn2 regulates protein synthesis by phosphorylation of translation initiation factor eIF2α, from yeast to mammals. The Gcn2 kinase domain (KD) is inherently inactive and requires allosteric stimulation by adjoining regulatory domains. Gcn2 contains a pseudokinase domain (YKD) required for high-level eIF2α phosphorylation in amino acid starved yeast cells; how...
متن کاملAn Alkaline Phosphatase Lacking Wheat Germ Agglutinin Binding Sites Useful Enzyme for Lectin Assays with Comparable Activity to the Calf Enzyme
Despite the availability of various alkaline phosphatase (ALP) isoenzymes, the calf enzyme is being used in current enzyme assays as the detector enzyme. The glycosylation pattern of this enzyme makes it a suitable ligand for binding to wheat germ agglutinin lectin (WGA). As a result of this property, the enzyme can not be used as a conjugate with this lectin, and the calf enzyme conjugates can...
متن کاملPolyamine derivatives as selective RNaseA mimics.
Site-selective scission of ribonucleic acids (RNAs) has attracted considerable interest, since RNA is an intermediate in gene expression and the genetic material of many pathogenic viruses. Polyamine-imidazole conjugates for site-selective RNA scission, without free imidazole, were synthesized and tested on yeast phenylalanine transfer RNA. These molecules catalyze RNA hydrolysis non-randomly. ...
متن کامل