Abstract 1950 Biochemical Characterization of the Human RNA-dependent ATPase DDX41

DDX41 is an essential DEAD-box helicase that is involved in necessary biological functions in gene regulation and immunity. It has been implicated in a variety of processes including R-loop regulation, cGAS inflammatory modulation, pre-mRNA splicing, and snoRNA + rRNA processing. Various germline and somatic mutations in the DDX41 gene have been linked to diseases like myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML). Despite the importance of DDX41's cellular functions, the underlying mechanisms and biochemistry of the enzyme require further investigation. This information is important for being able to predict the effect of specific mutations such as those found in MDS on DDX41 function. Here we use site-directed mutagenesis to produce seven different DDX41 variants with different missense mutations. We recombinantly expressed these variants in E. coli and used a multi-step purification scheme to obtain pure proteins. With these purified variants, we will characterize how specific mutations affect DDX41's nucleic acid binding/unwinding and ATP binding/hydrolysis activities. This knowledge will build our understanding of DDX41 and how mutations associated with diseases like MDS impact the enzyme function.