RT Journal Article
SR Electronic
T1 How the AFF1/4 scaffold recruits the elongation factor ELL2 to promote HIV-1 proviral transcription
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 068262
DO 10.1101/068262
A1 Shiqian Qi
A1 Zichong Li
A1 Ursula Schulze-Gahmen
A1 Goran Stjepanovic
A1 Qiang Zhou
A1 James H. Hurley
YR 2016
UL http://biorxiv.org/content/early/2016/08/06/068262.abstract
AB The intrinsically disordered scaffold proteins AFF1/4 and the transcription elongation factors ELL1/2 are core components of the superelongation complex required for HIV-1 proviral transcription. We determined the 2.0-Å resolution crystal structure of the human ELL2 C-terminal domain bound to its 50-residue binding site on AFF4, the ELLBow. The ELL2 domain has the same arch-shaped fold as the tight junction protein occludin. The ELLBow consists of an N-terminal helix followed by an extended hairpin that we refer to as the elbow joint, 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. The AFF4-ELL2 interface is imperfectly packed, leaving a cavity suggestive of a potential binding site for transcription-promoting small molecules.