The Elongator complex is a multifunction protein complex which has been shown to be involved in transcriptional elongation, DNA replication and repair, tubulin and histone acetylation, gene silencing and tranfer RNA u...The Elongator complex is a multifunction protein complex which has been shown to be involved in transcriptional elongation, DNA replication and repair, tubulin and histone acetylation, gene silencing and tranfer RNA uridine modification. The composition of the Elongator complex is found to be highly conserved in eukaryotes, protein homologs of various subunits have been identified in fungi, plant, animal, and human. Remarkably, mutation in genes encoding the Elongator complex structural components all results in defects of transfer RNA wobble uridine modification, and this function of the Elongator complex is also conserved in eukaryotes. The Elongator complex mutants in higher plants have pleiotropic phenotypes including defects in vegetative growth, abiscisic acid hypersensitivity, elevated tolerance to drought and oxidative stress. What is the relationship between the Elongator complex＇s function in nucleoside modification and its activity in other cellular pathways？ This review summarizes the recent advances in study of function of the Elongator complex, in the aspects of cell physiology and molecular biology.展开更多
Two multidentate ligands 2,9-di[6＇-（2″-hydroxyl-3″-methoxyphenyl）-n-2＇,5＇-diazahexyl]-1,10-phenanthroline（LA）and 2,9-di（6＇-α-phenol-n-2＇,5＇-diazahexyl）-1,10-phenanthroline（LB）were synthesized and full...Two multidentate ligands 2,9-di[6＇-（2″-hydroxyl-3″-methoxyphenyl）-n-2＇,5＇-diazahexyl]-1,10-phenanthroline（LA）and 2,9-di（6＇-α-phenol-n-2＇,5＇-diazahexyl）-1,10-phenanthroline（LB）were synthesized and fully characterized.Protonation of the ligands and the stability of the complexes of the ligands with divalent metal ions were investigated.The trinuclear metal complexes [Cu（Ⅱ）and Zn（Ⅱ）] of the ligands were studied,as catalysts,for the transphosphorylation of the RNA-model substrate 2-hydroxypropyl-p-nitrophenyl phosphate（HPNP）.The second-order rate constants of HPNP-hydrolysis catalyzed by M3L and M3LH-1 were obtained,which indicated that Zn3LBH-1 was the most efficient catalyst among them.The proposed mechanisms included the activation of the substrate via binding to the metal ions and intramolecular nucleophilic attack by the deprotonated C2-hydroxyl of HPNP.展开更多
A new ruthenium polypyridine complex, [Ru(phen) 2(pMIP)] 2+(phen=1,10-phenanthroline, pMIP=2-(4-methylphenyl)imidazo phenanthroline), was synthesized and characterized by elementary analysis, MS and 1H NMR. Spectrosco...A new ruthenium polypyridine complex, [Ru(phen) 2(pMIP)] 2+(phen=1,10-phenanthroline, pMIP=2-(4-methylphenyl)imidazo phenanthroline), was synthesized and characterized by elementary analysis, MS and 1H NMR. Spectroscopic methods have been carried out on the interaction mechanism of the Ru (Ⅱ) complex with yeast tRNA systematically. The experimental results indicate that the complex binds to yeast tRNA with an intercalative mode possibly, and interacts with yeast tRNA enantioselectively. The experimental results also suggest that spectroscopic method is effective on studying the interaction mechanism of Ru (Ⅱ) complexes with RNA. Information obtained from the study is potentially useful in the design of new RNA-targeting drugs.展开更多
The binding kinetics properties of three Ru（Ⅱ） complexes of [Ru（bpy） 2（dhipH 3）]（ClO4）2, [（bpy） 2Ru（eipcH）]（ClO4）2 and [（bpy） 2Ru（ebipcH 2）Ru（bpy） 2]（ClO4）4, where bpy2,2′-bipyridine, dhipH 33,...The binding kinetics properties of three Ru（Ⅱ） complexes of [Ru（bpy） 2（dhipH 3）]（ClO4）2, [（bpy） 2Ru（eipcH）]（ClO4）2 and [（bpy） 2Ru（ebipcH 2）Ru（bpy） 2]（ClO4）4, where bpy2,2′-bipyridine, dhipH 33,4-dihydroxyphenyl-（imidazo[4,5-f][1,10]phenanthroline）, eipcHN-ethyl-4-（imidazolo[4,5-f]-（1,10-phenanthrolin）-2-yl）carbazole, and ebipcH 2N-ethyl-4,7-bis（imidazolo[4,5-f]-（1,10-phenanthrolin）-2-yl）carbazole, with yeast-RNA were investigated by monitoring the decays in absorbance for π-π* absorption peaks at 286 nm with binding time. The decay curves for the complexes were well fitting to biexponential decay functions with half-life times for rapidly-decayed components being 0.006, 0.02 and 0.8 min, and those for slowly-decayed components being 0.7, 4.2 and 103 min, respectively. The rapidly- and slowly-decayed components are probably due to electrostatic interaction and aromatic base stacking of the RNA with the Ru（Ⅱ） complexes, respectively. The results indicate that not only binuclear complexes but also mononuclear complexes can slowly bind to the RNA depending on the molecular structures of the complexes.展开更多
基金supported by the National Natural Science Foundation of China (31100268 and 31270658)the Fundamental Research Funds for the Central Universities, China (2011PY108)the Scientific Research Foundation for the Returned Overseas Chinese Scholars, Ministry of Education, China
文摘The Elongator complex is a multifunction protein complex which has been shown to be involved in transcriptional elongation, DNA replication and repair, tubulin and histone acetylation, gene silencing and tranfer RNA uridine modification. The composition of the Elongator complex is found to be highly conserved in eukaryotes, protein homologs of various subunits have been identified in fungi, plant, animal, and human. Remarkably, mutation in genes encoding the Elongator complex structural components all results in defects of transfer RNA wobble uridine modification, and this function of the Elongator complex is also conserved in eukaryotes. The Elongator complex mutants in higher plants have pleiotropic phenotypes including defects in vegetative growth, abiscisic acid hypersensitivity, elevated tolerance to drought and oxidative stress. What is the relationship between the Elongator complex＇s function in nucleoside modification and its activity in other cellular pathways？ This review summarizes the recent advances in study of function of the Elongator complex, in the aspects of cell physiology and molecular biology.
基金Supported by the National Natural Science Foundation of China(Nos.20371028and20671052).
文摘Two multidentate ligands 2,9-di[6＇-（2″-hydroxyl-3″-methoxyphenyl）-n-2＇,5＇-diazahexyl]-1,10-phenanthroline（LA）and 2,9-di（6＇-α-phenol-n-2＇,5＇-diazahexyl）-1,10-phenanthroline（LB）were synthesized and fully characterized.Protonation of the ligands and the stability of the complexes of the ligands with divalent metal ions were investigated.The trinuclear metal complexes [Cu（Ⅱ）and Zn（Ⅱ）] of the ligands were studied,as catalysts,for the transphosphorylation of the RNA-model substrate 2-hydroxypropyl-p-nitrophenyl phosphate（HPNP）.The second-order rate constants of HPNP-hydrolysis catalyzed by M3L and M3LH-1 were obtained,which indicated that Zn3LBH-1 was the most efficient catalyst among them.The proposed mechanisms included the activation of the substrate via binding to the metal ions and intramolecular nucleophilic attack by the deprotonated C2-hydroxyl of HPNP.
文摘A new ruthenium polypyridine complex, [Ru(phen) 2(pMIP)] 2+(phen=1,10-phenanthroline, pMIP=2-(4-methylphenyl)imidazo phenanthroline), was synthesized and characterized by elementary analysis, MS and 1H NMR. Spectroscopic methods have been carried out on the interaction mechanism of the Ru (Ⅱ) complex with yeast tRNA systematically. The experimental results indicate that the complex binds to yeast tRNA with an intercalative mode possibly, and interacts with yeast tRNA enantioselectively. The experimental results also suggest that spectroscopic method is effective on studying the interaction mechanism of Ru (Ⅱ) complexes with RNA. Information obtained from the study is potentially useful in the design of new RNA-targeting drugs.
文摘The binding kinetics properties of three Ru（Ⅱ） complexes of [Ru（bpy） 2（dhipH 3）]（ClO4）2, [（bpy） 2Ru（eipcH）]（ClO4）2 and [（bpy） 2Ru（ebipcH 2）Ru（bpy） 2]（ClO4）4, where bpy2,2′-bipyridine, dhipH 33,4-dihydroxyphenyl-（imidazo[4,5-f][1,10]phenanthroline）, eipcHN-ethyl-4-（imidazolo[4,5-f]-（1,10-phenanthrolin）-2-yl）carbazole, and ebipcH 2N-ethyl-4,7-bis（imidazolo[4,5-f]-（1,10-phenanthrolin）-2-yl）carbazole, with yeast-RNA were investigated by monitoring the decays in absorbance for π-π* absorption peaks at 286 nm with binding time. The decay curves for the complexes were well fitting to biexponential decay functions with half-life times for rapidly-decayed components being 0.006, 0.02 and 0.8 min, and those for slowly-decayed components being 0.7, 4.2 and 103 min, respectively. The rapidly- and slowly-decayed components are probably due to electrostatic interaction and aromatic base stacking of the RNA with the Ru（Ⅱ） complexes, respectively. The results indicate that not only binuclear complexes but also mononuclear complexes can slowly bind to the RNA depending on the molecular structures of the complexes.
