Purity ~85% (SDS-PAGE). POLR2I, also known as RPB9, belongs to the archaeal rpoM/eukaryotic RPA12/RPB9/RPC11 RNA polymerase family. This protein is a subunit of RNA polymerase II, the polymerase responsible for synthesizing messenger RNA in eukaryotes. DNA-dependent RNA polymerase catalyzes the transcription of DNA into RNA using the four ribonucleoside triphosphates as substrates. Also it is synthesizes mRNA precursors and many functional non-coding RNAs. Source: Recombinant protein corresponding to aa1-125 from human PORL2I, fused to His-tag at N-terminal expressed in E. coli. Molecular Weight: ~17kD (148aa) AA