6Q6R

Recognition of different base tetrads by RHAU: X-ray crystal structure of G4 recognition motif bound to the 3-end tetrad of a DNA G-quadruplex

Summary for 6Q6R

• Entry DOI: 10.2210/pdb6q6r/pdb
• Descriptor: Parallel stranded DNA G-quadruplex, ATP-dependent DNA/RNA helicase DHX36, POTASSIUM ION, ... (4 entities in total)
• Functional Keywords: g-quadruplex; x-ray crystallography; rhau helicase; dhx36; g4r1; mle1; deah-box family., dna binding protein
• Biological source: unidentified; More
• Total number of polymer chains: 8
• Total formula weight: 34655.76

Authors

Heddi, B.,Cheong, V.V.,Schmitt, E.,Mechulam, Y.,Phan, A.T. (deposition date: 2018-12-11, release date: 2019-10-16, Last modification date: 2024-01-24)

Primary citation

Heddi, B.,Cheong, V.V.,Schmitt, E.,Mechulam, Y.,Phan, A.T.
Recognition of different base tetrads by RHAU (DHX36): X-ray crystal structure of the G4 recognition motif bound to the 3'-end tetrad of a DNA G-quadruplex.
J.Struct.Biol., 209:107399-107399, 2020

PubMed Abstract: G-quadruplexes (G4) are secondary structures of nucleic acids that can form in cells and have diverse biological functions. Several biologically important proteins interact with G-quadruplexes, of which RHAU (or DHX36) - a helicase from the DEAH-box superfamily, was shown to bind and unwind G-quadruplexes efficiently. We report a X-ray co-crystal structure at 1.5 Å resolution of an N-terminal fragment of RHAU bound to an exposed tetrad of a parallel-stranded G-quadruplex. The RHAU peptide folds into an L-shaped α-helix, and binds to a G-quadruplex through π-stacking and electrostatic interactions. X-ray crystal structure of our complex identified key amino acid residues important for G-quadruplex-peptide binding interaction at the 3'-end G•G•G•G tetrad. Together with previous solution and crystal structures of RHAU bound to the 5'-end G•G•G•G and G•G•A•T tetrads, our crystal structure highlights the occurrence of a robust G-quadruplex recognition motif within RHAU that can adapt to different accessible tetrads.

PubMed: 31586599
DOI: 10.1016/j.jsb.2019.10.001

Experimental method

X-RAY DIFFRACTION (1.5 Å)