Prokaryotic and Eukaryotic Proteins

Mike Gene authored this which I would recommend. His italicized comments follow.


Previously, we noted that eukaryotic proteins are typically larger than prokaryotic proteins and now we can see why: eukaryotes are just better at making multi-domain proteins. Thus, it is not surprising that they could synthesize the artificial two-domain GFP protein when bacteria could not. But there is more.

There is a particular type of multi-domain protein known as the multi-domain repeat. In this case, a single type of domain is repeated multiple times within the same amino acid chain. For example, imagine a protein that had three or more GFP-like folds all linked together. Not only are eukaryotes better at making this type of protein, but it is also more commonly found in multicellular organisms, where approximately one out of every ten multicellular proteins is a multi-domain repeat. In fact, with this criterion alone, unicellular yeast are more like bacteria than humans.

Viewing a matter from a different perspective can yield some uncommon insight.