Table 1. Summary of soaking conditions and ligand occupancy for crystals soaked in d-amino acids.

Ligand(s)	pdb code	Soaking conditions	Site 1 ligand	Site 2 ligand	Site 3 ligand
d-Phe	5E2L	2.5 mM, 24 h	d-Phe	Water/ions	Water/ions
d-Tyr	5E40	1.6 mM final a	d-Tyr	Water/ions	Water/ions
d-Tyr	5E4N	5 mM, 24 h	d-Tyr	Water/ions	d-Tyr
l-Phe, d/l-Trp	5E7Z	0.25 mM l-Phe, 2.5 mM d/l-Trp, 24 h b	l-Phe	d/l-Trp	Water/ions
d-Trp	5E5G	10 mM d-Trp, 24 h	d-Trp	d-Trp	Waters/Ions

^a two additions of 0.2 μL of a 10 mM D-Tyr stock solution to a 2 μL drop, 24 hours between first and second addition and 24 hours between second addition and crystal freezing.

^b soaked in l-Phe and d-Trp (Acros, 92%ee by HPLC), which resulted in electron density in the Trp site which was modelled as d- and l-Trp at 50% occupancy each.