Other options to explore here include f
unctional families,
structural neighborhoods, etc. We will use some of these later. For now, you are welcome to do your research and compare the findings for this domain with the same features of the other two domains. You will discover, for example, that the second domain, 3.20.20.60 belongs to the phosphoenolpyruvate-binding domain superfamily that has considerably higher diversity than the C-terminal domain.
There are many questions one can ask while exploring this database. For example, it would be interesting to know if the structures of these three domains are equally conserved within their families, what functions (enzymatic activity or something else) are assigned to them, and to compare the conservation of sequence and structure. This will give exciting insights into the structure and function of pyruvate kinase.
There are also two links on the right side of the page, one to the Proteopedia page that describes pyruvate kinase and the second to PDBsum. In the next section, I will show some valuable features of PDBsum.