Crystal structures of the N-terminal domain of the Staphylococcus aureus DEAD-box RNA helicase CshA and its complex with AMP

In this study, the crystal structures of the N-terminal RecA-like domain 1 of S. aureus CshA (SaCshAR1) and of its complex with AMP (SaCshAR1 – AMP) are reported at resolutions of 1.5 and 1.8   Å , respectively. SaCshAR1 adopts a conserved α / β RecA-like structure with seven parallel strands surrounded by nine α -helices. The Q motif and motif I are responsible for the binding of the adenine group and phosphate group of AMP, respectively. Structure comparison of SaCshAR1 – AMP and SaCshAR1 reveals that motif I undergoes a conformational change upon AMP binding. Isothermal titration calorimetry assays further conformed the essential roles of Phe22 in the Q motif and Lys52 in motif I for binding ATP, indicating a conserved substrate-binding mechanism in SaCshA compared with other DEAD-box RNA helicases.
Source: Acta Crystallographica Section F - Category: Biochemistry Authors: Tags: CshA DEAD-box RNA helicase Staphylococcus aureus AMP crystallography research communications Source Type: research