Fig 6. Functional relevance of the B4GalT1 homodimers.

Monomers within the dimer are displayed with the surface representation and colored gray. Key residues and regions are highlighted as follows: Lid (red), loop1 (blue), Trp310 (orange), Asp315 (purple), Met340 (yellow), His343 (green). Darker color tints are used for the second monomer in the dimer. (a). Relative positions of the active site positions (black arrows) in the B4GalT1 homodimer structure (PDB code 6FWU). (b). Model of a B4GalT1 dimer with one chain in an active conformation (including the donor UDP-Gal, acceptor GlcNAc and Mn²⁺ ion from PDB codes 1O0R and 4EE4, respectively) on the B4GalT1 homodimer structure (PDB code 6FWU) with reconstructed lid.