<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">Hello,<div><br></div><div><span class="Apple-tab-span" style="white-space: pre; ">                </span>I am trying to a simple energy minimization with my DNA molecule I created with 3DNA program. Below is a snippet of a pdb file where I've only included coordinates for one residue to save space (<i>Actual file contains coordinates for 12-mer DNA</i>).</div><div><br></div><div>So my question is why is the pdb2gmx spitting out <b>Fatal Error: Atom P in residue DG 0 not found in rtp entry entry DGN with 32 atoms while sorting atoms?</b> I am using forcefield94 and looking at the .rtp file and atom P is surely present in the forcefield. Is the pdb format? Something else?</div><div><br></div><div>If it the format then does anyone know how to properly put together a pdb file of a nucleic acid and show me what it looks like, and what forcefields are good for DNA ligand interactions?</div><div><br></div><div>thanks in advance</div><div><br></div><div><div>REMARK 3DNA (v1.5, Nov. 2002) by Xiang-Jun Lu at Wilma K. Olson's Lab.</div><div>ATOM 1 P DG A 1 -0.356 9.218 1.848</div><div>ATOM 2 O1P DG A 1 -0.311 10.489 2.605</div><div>ATOM 3 O2P DG A 1 -1.334 9.156 0.740</div><div>ATOM 4 O5' DG A 1 1.105 8.869 1.295</div><div>ATOM 5 C5' DG A 1 2.021 8.156 2.146</div><div>ATOM 6 C4' DG A 1 2.726 7.072 1.355</div><div>ATOM 7 O4' DG A 1 1.986 5.817 1.352</div><div>ATOM 8 C3' DG A 1 2.952 7.370 -0.127</div><div>ATOM 9 O3' DG A 1 4.210 6.832 -0.518</div><div>ATOM 10 C2' DG A 1 1.848 6.598 -0.850</div><div>ATOM 11 C1' DG A 1 1.913 5.344 0.016</div><div>ATOM 12 N9 DG A 1 0.711 4.472 -0.101</div><div>ATOM 13 C8 DG A 1 -0.606 4.826 -0.294</div><div>ATOM 14 N7 DG A 1 -1.430 3.807 -0.354</div><div>ATOM 15 C5 DG A 1 -0.599 2.700 -0.190</div><div>ATOM 16 C6 DG A 1 -0.914 1.317 -0.165</div><div>ATOM 17 O6 DG A 1 -2.010 0.775 -0.284</div><div>ATOM 18 N1 DG A 1 0.233 0.533 0.025</div><div>ATOM 19 C2 DG A 1 1.516 1.023 0.172</div><div>ATOM 20 N2 DG A 1 2.476 0.111 0.344</div><div>ATOM 21 N3 DG A 1 1.811 2.321 0.149</div><div>ATOM 22 C4 DG A 1 0.709 3.095 -0.035</div><div>END</div></div></body></html>