Malac, Kamil; Barvik, Ivan
Complex between Human RNase HI and the phosphonate-DNA/RNA duplex: Molecular dynamics study
JOURNAL OF MOLECULAR GRAPHICS & MODELLING, 44:81-90, JUL 2013

Our 200 ns MD simulations show that even fully modified oligonucleotides bearing the 3'-O-P-CH2-O-5' (but not 3'-O-CH2-P-O-5') phosphonate linkages can be successfully attached to the surface of Human RNase H. It enables to explain that oligonucleotides consisting of the alternating 3'-O-P-CH2-O-5' phosphonate and phosphodiester linkages are capable to elicit the RNase H activity (while the 3'-O-CH2-P-O-5' phosphonates are completely inactive). Stability of the binuclear active site of Human RNase H was achieved using the one-atom model for Mg2+ in conjunction with a polarized phosphate group of the scissile bond, which is wedged between both magnesium ions. The reference MD simulation (lasting for 1000 ns), which was produced using a well-established seven-point (with dummy atoms) model for Mg2+ led to essentially the same results. The MD run (lasting for 500 ns) produced for the Therms thermophilus Argonaute enzyme shows the transferability of our approach for the stabilization of a binuclear active site. Glu512 was bound in the T. thermophilus Argonaute active site to the 2'-OH of the nucleotide adjacent to the scissile phosphate and one of the two active-site divalent metal ions in exactly the same way as Glu186 in Human RNase H. Glu512 thus completes the catalytic tetrad of Argonaute. (C) 2013 Elsevier Inc. All rights reserved.

DOI:10.1016/j.jmgm.2013.05.004

Find full text with Google Scholar.