"Study reports the 2.0-A resolution crystal structure of the human ELL2 C-terminal domain bound to its 50-residue binding site on AFF4 the ELLBow. The ELLBow consists of an N-terminal helix followed by an extended hairpin and occupies most of the concave surface of ELL2. This surface is important for the ability of ELL2 to promote HIV-1 Tat-mediated proviral transcription."xsd:string