Search for entries in the PDB by structure title. Structure titles are found in the TITLE record of the PDB file and the _struct.title field of the mmCIF file.
Choose the desired option from the pull down menu ("Contains", "Equals", etc.) and enter the search term in the text box. In most cases, the default "Contains" will be the most useful option (if you choose "Equals" the search term must exactly match the full title).
Select Contains from the pull down menu and type skeletal in the text box. Press "Submit Query".
The Query Result Browser page will show all structures that contain skeletal in the structure title.
From the "Query Options" pull down menu at the top of the Query Results Browser page, choose "Refine/Modify Query".
Select Structure Title again, then Does NOT Contain, and type troponin in the text box. Press. "Submit Query".
The Query Result browser will show all structures that contain skeletal, but not troponin in the structure title.