SNAP output for PDB entry 4gg4 [SNAP web server]

PDB-id

4gg4; SNAP-derived features in text and JSON formats; DNAproDB

Class

DNA binding protein-DNA-RNA

Method

X-ray (2.501 Å)

Summary

Crystal structure of the tal effector dhax3 bound to specific DNA-RNA hybrid

Reference

Yin P, Deng D, Yan C, Pan XJ, Xi JJ, Yan N, Shi Y (2012): "Specific DNA-RNA hybrid recognition by TAL effectors." Cell Rep, 2, 707-713. doi: 10.1016/j.celrep.2012.09.001.

Abstract

The transcription activator-like (TAL) effector targets specific host promoter through its central DNA-binding domain, which comprises multiple tandem repeats (TALE repeats). Recent structural analyses revealed that the TALE repeats form a superhelical structure that tracks along the forward strand of the DNA duplex. Here, we demonstrate that TALE repeats specifically recognize a DNA-RNA hybrid where the DNA strand determines the binding specificity. The crystal structure of a designed TALE in complex with the DNA-RNA hybrid was determined at a resolution of 2.5 Å. Although TALE repeats are in direct contact with only the DNA strand, the phosphodiester backbone of the RNA strand is inaccessible by macromolecules such as RNases. Consistent with this observation, sequence-specific recognition of an HIV-derived DNA-RNA hybrid by an engineered TALE efficiently blocked RNase H-mediated degradation of the RNA strand. Our study broadens the utility of TALE repeats and suggests potential applications in processes involving DNA replication and retroviral infections.