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Full-Text Articles in Cell and Developmental Biology

Impact Of Mtr4 Structural Domains On Its Enzymatic Activities, In The Regulation Of Nuclear Rna Turnover, Li Yan Oct 2014

Impact Of Mtr4 Structural Domains On Its Enzymatic Activities, In The Regulation Of Nuclear Rna Turnover, Li Yan

Dissertations (1934 -)

RNA processing and turnover plays an important role in RNA maturation, metabolism and quality control, which contribute to gene regulation and cell health. The TRAMP complex, composed of an RNA binding protein Air2p, a poly-A polymerase Trf4p, and a RNA helicase Mtr4p, assist nuclear exosome-dependent RNA processing and degradation in Saccharomyces cerevisiae, like tRNAiMet turnover, 5'ETS degradation and rRNA processing. Mtr4p structure reveals a novel protruding arch domain, which contains the recognizable KOW domain and a stalk domain. Except for the two conserved RecA-like helicase domains, the helicase core contains two other structural domains, a winged helix that connects arch …


Kinetics And Relative Importance Of Phosphorolytic And Hydrolytic Cleavage Of Cellodextrins And Cellobiose In Cell Extracts Of Clostridium Thermocellum, Yie.-Heng P. Zhang, Lee R. Lynd Dec 2004

Kinetics And Relative Importance Of Phosphorolytic And Hydrolytic Cleavage Of Cellodextrins And Cellobiose In Cell Extracts Of Clostridium Thermocellum, Yie.-Heng P. Zhang, Lee R. Lynd

Dartmouth Scholarship

Rates of phosphorolytic cleavage of 􏰁-glucan substrates were determined for cell extracts from Clostridium thermocellum ATCC 27405 and were compared to rates of hydrolytic cleavage. Reactions with cellopentaose and cellobiose were evaluated for both cellulose (Avicel)- and cellobiose-grown cultures, with more limited data also obtained for cellotetraose. To measure the reaction rate in the chain-shortening direction at elevated temper- atures, an assay protocol was developed featuring discrete sampling at 60°C followed by subsequent analysis of reaction products (glucose and glucose-1-phosphate) at 35°C. Calculated rates of phosphorolytic cleavage for cell extract from Avicel-grown cells exceeded rates of hydrolytic cleavage by >20-fold …