<HTML><BODY style="word-wrap: break-word; -khtml-nbsp-mode: space; -khtml-line-break: after-white-space; "><BR><DIV><DIV>On Mar 8, 2006, at 2:22 PM, Todd T Talley wrote:</DIV><BLOCKQUOTE type="cite"><SPAN class="Apple-style-span" style="border-collapse: separate; border-spacing: 0px 0px; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 16px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; text-align: auto; -khtml-text-decorations-in-effect: none; text-indent: 0px; -apple-text-size-adjust: auto; text-transform: none; orphans: 2; white-space: normal; widows: 2; word-spacing: 0px; "><O:SMARTTAGTYPE namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="PlaceName"><O:SMARTTAGTYPE namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="PlaceType"><O:SMARTTAGTYPE namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="City"><O:SMARTTAGTYPE namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="place"><O:SMARTTAGTYPE namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="PersonName"><DIV class="Section1"><P class="MsoNormal"><FONT size="3" color="black" face="Arial"><SPAN style="font-size: 12.0pt; font-family: Arial; "><SPAN class="Apple-style-span" style="font-family: Arial; ">Hay,</SPAN></SPAN></FONT></P></DIV></O:SMARTTAGTYPE></O:SMARTTAGTYPE></O:SMARTTAGTYPE></O:SMARTTAGTYPE></O:SMARTTAGTYPE></SPAN></BLOCKQUOTE><BLOCKQUOTE type="cite"><SPAN class="Apple-style-span" style="border-collapse: separate; border-spacing: 0px 0px; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 16px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; text-align: auto; -khtml-text-decorations-in-effect: none; text-indent: 0px; -apple-text-size-adjust: auto; text-transform: none; orphans: 2; white-space: normal; widows: 2; word-spacing: 0px; "><O:SMARTTAGTYPE namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="PlaceName"><O:SMARTTAGTYPE namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="PlaceType"><O:SMARTTAGTYPE namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="City"><O:SMARTTAGTYPE namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="place"><O:SMARTTAGTYPE namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="PersonName"><DIV class="Section1"><P class="MsoNormal"><FONT class="Apple-style-span" face="Arial"></FONT></P><P class="MsoNormal"><FONT size="3" color="black" face="Arial"><SPAN style="font-size: 12.0pt; font-family: Arial; "><SPAN class="Apple-style-span" style="font-family: Arial; "> Sorry to bother you, but you were so helpful last week I thought that I would try again. Is there a way to show the carbonyl of the backbone of a specific residue? I would like to show the H bond between my ligand and a specific Trp. </SPAN></SPAN></FONT></P></DIV></O:SMARTTAGTYPE></O:SMARTTAGTYPE></O:SMARTTAGTYPE></O:SMARTTAGTYPE></O:SMARTTAGTYPE></SPAN></BLOCKQUOTE>Well, the vanilla answer is (if we're talking about residue 12.A for example) "disp :12.a@c,o". However, I'm guessing that the reason you've undisplayed the carbonyl in the first place is because you're showing a ribbon -- in which case there are a few more useful things to know. By default the ribbon depiction replaces the backbone atoms (including the carbonyl oxygen) so even if you turn the display of specific backbone atoms back on (e.g. with the above "disp" command), no atoms will be shown. However, Chimera will know that these atoms are now "displayed" and will begin to show things such as H-bonds that involve those atoms (drawing the end of the H-bond to the interpolated ribbon position of the backbone atom). You can force backbone atoms to be explicitly depicted even in the presence of a ribbon with the "ribbackbone" command (e.g. "ribbackbone :12.a") -- they will be shown at their normal non-interpolated positions.<BR></DIV><DIV><BR class="khtml-block-placeholder"></DIV><DIV>--Eric</DIV><DIV><BR class="khtml-block-placeholder"></DIV></BODY></HTML>