It seems many SE sites have some sort of concept of what I call "sub-tags", but it seems to be slightly different for this site as one tag literally is a subset of another. Granted, I know that there are 'ribozymes' that are enzymes made from RNA, but >99% of all enzymes are proteins to my knowledge. Since enzymes are almost an exact subset of proteins, should all enzyme questions be tagged proteins as well?
Perhaps a better solution to avoid this redundancy would be to only tag proteins if the question actually relates strongly to what proteins are and not just what certain enzymes do. However, it can be nice to have all protein related questions under one tag to make them easily searchable.
What are your thoughts on this? How should "sub-tags" be used on this site?
Example question on this site: How does ATP-Synthase work?