Crystal structure of Prp16 in complex with ADP.

DEAH‐box helicases play a crucial role in pre‐mRNA splicing as they are responsible for major rearrangements of the spliceosome and are involved in various quality‐ensuring steps. Prp16 is the driving force during spliceosomal catalysis, remodeling the C state into the C* state. Here, the first crystal structure of Prp16 from Chaetomium thermophilum in complex with ADP is reported at 1.9 Å resolution. Comparison with the other spliceosomal DEAH‐box helicases Prp2, Prp22 and Prp43 reveals an overall identical domain architecture. The β‐hairpin, which is a structural element of the RecA2 domain, exhibits a unique position, punctuating its flexibility. Analysis of cryo‐EM models of spliceosomal complexes containing Prp16 reveals that these models show Prp16 in its nucleotide‐free state, rendering the model presented here the first structure of Prp16 in complex with a nucleotide. [ABSTRACT FROM AUTHOR]