This refers specifically to BubbaBear_gp56. A question posed by Dr. Herren (Kansas State U): Isn't this a dihydrofolate reductase rather than a thymidylate synthase.

First I scanned this website
From this I learned that they often come together.
However, when both parts are there, I think it is a much larger protein, with PDB citing residues of 159-384 for the DR crystal structure and 1042 – 2084 residues for the TS structure.
It looks like this is aligning with the DR domains and not the TS. So I would call BubbaBear gp 56 a "dihydrofolate reductase"!