Potent second-generation thrombin aptamers adopt a duplex– quadruplex bimodular folding and recognize thrombin exosite II with very high affinity and specificity. A sound model of these oligonucleotides, either free or in complex with thrombin, is not yet available. Here, a structural study of one of these aptamers, HD22-27mer, is presented. The crystal structure of this aptamer in complex with thrombin displays a novel architecture in which the helical stem is enchained to a pseudo-G-quadruplex. The results also underline the role of the residues that join the duplex and quadruplex motifs and control their recruitment in thrombin binding.
Duplex-quadruplex motifs in a peculiar structural organization cooperatively contribute to thrombin binding of a DNA aptamer / RUSSO KRAUSS, Irene; Pica, Andrea; Merlino, Antonello; L., Mazzarella; Sica, Filomena. - In: ACTA CRYSTALLOGRAPHICA. SECTION D, BIOLOGICAL CRYSTALLOGRAPHY. - ISSN 0907-4449. - 69:12(2013), pp. 2403-2411. [10.1107/S0907444913022269]
Duplex-quadruplex motifs in a peculiar structural organization cooperatively contribute to thrombin binding of a DNA aptamer
RUSSO KRAUSS, IRENE;PICA, ANDREA;MERLINO, ANTONELLO;SICA, FILOMENA
2013
Abstract
Potent second-generation thrombin aptamers adopt a duplex– quadruplex bimodular folding and recognize thrombin exosite II with very high affinity and specificity. A sound model of these oligonucleotides, either free or in complex with thrombin, is not yet available. Here, a structural study of one of these aptamers, HD22-27mer, is presented. The crystal structure of this aptamer in complex with thrombin displays a novel architecture in which the helical stem is enchained to a pseudo-G-quadruplex. The results also underline the role of the residues that join the duplex and quadruplex motifs and control their recruitment in thrombin binding.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.