Auxiliary Factors and RNA Substrates Regulate Dead-Box Protein Activity by Modulation of the Dead-Box Protein Conformational Cycle

The DEAD box protein eIF4A. 2. A cycle of nucleotide and RNA-dependent conformational changes.

Limited proteolysis experiments have been carried out with the DEAD box protein eIF4A. The results suggest that there is a substantial conformational change in eIF4A upon binding single-stranded RNA. Binding of ADP induces conformational changes in the free enzyme and the enzyme.RNA complex, and binding of the ATP analogue AMP-PNP induces a conformational change in the enzyme.RNA complex. The p...

eIF4G stimulates the activity of the DEAD box protein eIF4A by a conformational guidance mechanism

The activity of eIF4A, a key player in translation initiation, is regulated by other translation factors through currently unknown mechanisms. Here, we provide the necessary framework to understand the mechanism of eIF4A's regulation by eIF4G. In solution, eIF4A adopts a defined conformation that is different from the crystal structure. Binding of eIF4G induces a 'half-open' conformation by int...

Ddx42p—a human DEAD box protein with RNA chaperone activities

The human gene ddx42 encodes a human DEAD box protein highly homologous to the p68 subfamily of RNA helicases. In HeLa cells, two ddx42 poly(A)+ RNA species were detected both encoding the nuclear localized 938 amino acid Ddx42p polypeptide. Ddx42p has been heterologously expressed and its biochemical properties characterized. It is an RNA binding protein, and ATP and ADP modulate its RNA bindi...

The DEAD Box Protein elF 4 A . 2 . A Cycle of Nucleotide and RNA - Dependent Conformational Changes

Discriminatory RNP remodeling by the DEAD-box protein DED1.

DExH/D proteins catalyze NTP-driven rearrangements of RNA and RNA-protein complexes during most aspects of RNA metabolism. Although the vast majority of DExH/D proteins displays virtually no sequence-specificity when remodeling RNA complexes in vitro, the enzymes clearly distinguish between a large number of RNA and RNP complexes in a physiological context. It is unknown how this discrimination...