<html><head><meta http-equiv="Content-Type" content="text/html charset=windows-1252"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class="">Hi Joshua,<div class=""><br class=""></div><div class=""> Eric looked at the code and said the changechains command can’t change the blank chain id because it won’t accept a quoted space character as the chain letter. It could be done with Python code, or as you mention you can do it with the change chain ids gui.</div><div class=""><br class=""></div><div class=""><span class="Apple-tab-span" style="white-space:pre"> </span>Tom</div><div class=""><br class=""></div><div class=""><br class=""><div><blockquote type="cite" class=""><div class="">On Oct 20, 2015, at 2:07 PM, Broyde, Joshua E. <wrote:</div><br class="Apple-interchange-newline"><div class=""><div style="font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; direction: ltr; font-family: Tahoma; font-size: 10pt;" class="">Dear Tom,<div class="">Hope you are well. I am having an issue with redefining the chains in a pdb open in Chimera. If a model has two chains (A and B) then it is easy to reassign the chain ids using:</div><div class=""><b style="font-family: Times; font-size: 12px;" class="">changechains A,B B,A</b></div><div class=""><b style="font-family: Times; font-size: 12px;" class=""><br class=""></b></div><div class="">However, if one of the chains does<span class="Apple-converted-space"> </span><b class="">not<span class="Apple-converted-space"> </span></b>have a chain id already, (what Chimera calls, the "principle chain"), how do I assign a chain id? This is easy to do in the GUI, but I cannot find a command for doing so.</div><div class=""><br class=""></div><div class="">Sincerely,</div><div class="">Joshua Broyde</div></div></div></blockquote></div><br class=""></div></body></html>