BLM helicase protein negatively regulates stress granule formation through unwinding RNA G-quadruplex structures

We ran native 5% polyacrylamide-TBE gel for electro mobility shift assay (EMSA) for DNA/RNA G4 structures with or without recombinant human core-BLM (cBLM) protein, which was extracted and purified from E.coli in order to show binding of the RNA/DNA by this protein. To further evidence, we cut the equivalent gel area where the shifted band is located for all the wells (DNA only, DNA+cBLM, RNA, RNA+cBLM and cBLM only) and anlayzed by LC-MS/MS to identify human BLM and to see if there are some E.coli contaminations in those specific bands. Moreover, we analyzed the stock solution of the recombinant cBLM as general control.