DSSR-derived G-quadruplex features in PDB entry 5ew2
Poster "DSSR-Enabled Automatic Identification and Annotation of G-quadruplexes in the PDB" presented at the RNA2020 online meeting
Citation: before a paper dedicated to the DSSR-G4 module comes out, please cite the 2015 DSSR paper published in Nucleic Acids Research.
- X-ray (3.59 Å)
- Human thrombin sandwiched between two DNA aptamers: hd22 and hd1-deltat12
- Pica, A., Russo Krauss, I., Parente, V., Tateishi-Karimata, H., Nagatoishi, S., Tsumoto, K., Sugimoto, N., Sica, F.: (2017) "Through-bond effects in the ternary complexes of thrombin sandwiched by two DNA aptamers." Nucleic Acids Res., 45, 461-469.
- Aptamers directed against human thrombin can selectively bind to two different exosites on the protein surface. The simultaneous use of two DNA aptamers, HD1 and HD22, directed to exosite I and exosite II respectively, is a very powerful approach to exploit their combined affinity. Indeed, strategies to link HD1 and HD22 together have been proposed in order to create a single bivalent molecule with an enhanced ability to control thrombin activity. In this work, the crystal structures of two ternary complexes, in which thrombin is sandwiched between two DNA aptamers, are presented and discussed. The structures shed light on the cross talk between the two exosites. The through-bond effects are particularly evident at exosite II, with net consequences on the HD22 structure. Moreover, thermodynamic data on the binding of the two aptamers are also reported and analyzed.
- G4 notes
- 3 G-tetrads, 1 G4 helix, 1 G4 stem · 2(+Ln+Lw+Ln), chair(2+2), UDUD
1 glyco-bond=-s-s groove=wnwn planarity=0.756 type=bowl nts=4 GGGG D.DG8,D.DG20,D.DG17,D.DG11 2 glyco-bond=s-s- groove=wnwn planarity=0.637 type=bowl nts=4 GGGG E.DG1,E.DG15,E.DG10,E.DG6 3 glyco-bond=-s-s groove=wnwn planarity=0.543 type=other nts=4 GGGG E.DG2,E.DG14,E.DG11,E.DG5
Helix#1, 2 G-tetrad layers, INTRA-molecular, with 1 stem
Stem#1, 2 G-tetrad layers, 3 loops, INTRA-molecular, UDUD, anti-parallel, 2(+Ln+Lw+Ln), chair(2+2)
List of 3 non-stem G4-loops (including the two closing Gs)
1 type=lateral helix=#-1 nts=4 GTAG D.DG8,D.DT9,D.DA10,D.DG11 2 type=lateral helix=#-1 nts=7 GGGCAGG D.DG11,D.DG12,D.DG13,D.DC14,D.DA15,D.DG16,D.DG17 3 type=lateral helix=#-1 nts=4 GTTG D.DG17,D.DT18,D.DT19,D.DG20