Protein PDB/CIF text file reader that can fold a same section into one line Is there a software that can recognise the protein PDB/CIF files, and fold multiple lines of a same section into one line, so that it is easier to handle? I need to understand the format in CIF so as to create my own CIF file.

For example, when Notepad++ is used to read a .py file, it can fold the same section into one line. 

So for a PDB/CIF file, e.g. all the atom lines for a same chain can be folded into one line, and I can expand it if needed.

Like this picture, assuming "This PC" is the whole protein, while the other objects are the different chains.
Programs that work with PDB and mmCIF files may present the structure as a tree, for example:



(this is a Find dialog from ccp4MG)

but I'd be surprised if a text editor had such a feature. Normally, you don't edit PDB files in a text editor.