pfkfb3 cofactor

[hannahbaumann]

The crystal structure 6HVI has a 6-O-phosphono-beta-D-fructofuranose (F6P), a pyrophosphate and a citrate as cofactors. Included here is the pyrophosphate and the F6P.

• Should the citrate also be included?
• In the Hahn et al. dataset, no cofactors were included here
• in the Schrodinger dataset, a phosphate is included instead of the pyrophosphate (https://github.com/schrodinger/public_binding_free_energy_benchmark/blob/main/fep_benchmark_inputs/structure_inputs/merck/pfkfb3_automap_protein.pdb)