phosphorylation of RNA polymerase II C-terminal domain serine 5 residues (Q22257101)
The process of introducing a phosphate group onto a serine residue at position 5 within the heptapeptide repeat (YSPTSPS) of the C-terminal domain of RNA polymerase II. Typically, phosphorylation of serine 5 (Ser5) occurs near the 5' ends of genes. I