Table 1. Restraint-target values and the corresponding model interatomic distances for the MET–TYR and TYR–TRP covalent linkages in the models with PDB codes 1sj2 and 5jhy, as shown in Fig. 6 ▸ .

Target values correspond to the default value that is used by REFMAC5 in the absence of an explicit link dictionary and the value reported in the AceDRG link dictionary. Interatomic distances are shown for the deposited models, the models re-refined without a link record, re-refined with a link record but without a link dictionary and re-refined with an AceDRG link dictionary. Restraint-target estimated standard deviations (e.s.d.s) are shown in parentheses.

	MET–TYR	TYR–TRP
Target
Default	1.610 Å (0.020)	1.460 Å (0.020)
AceDRG	1.795 Å (0.010)	1.486 Å (0.011)
PDB entry 1sj2 (2.4 Å)
Deposited	1.73 Å	1.50 Å
Re-refined: no link	2.42 Å	2.10 Å
Re-refined: link record	1.70 Å	1.54 Å
Re-refined: AceDRG dictionary	1.81 Å	1.47 Å
PDB entry 5jhy (1.4 Å)
Deposited	1.82 Å	1.74 Å
Re-refined: no link	1.82 Å	1.73 Å
Re-refined: link record	1.76 Å	1.62 Å
Re-refined: AceDRG dictionary	1.78 Å	1.51 Å