Table 1.

Statistics for the structure determinations of the structured states of E. coli apo-IscU(WT) and apo-IscU(D39A).

IscU Variants [PDB]	WT [2L4X]	D39A [2KQK]
Distance constratins
Intraresidue (i = j)	218	305
Sequential (i–j = 1)	446	559
Medium range (1 < (i–j) ≤ 5)	416	525
Long range (i–j > 5)	621	713
Total	1701	2102
Dihedral angle constraints
φ	82	77
ψ	83	77
Number of 1DNH RDC constraints	22	16
Number of constraints per residue	14.9	17.9
Number of long range constraints per residue	4.9	5.6
CYANA target function (Å)	1.00 (± 0.10)	0.98 (± 0.18)
Average number of distance constraints violations per conformer (> 0.2 Å)	0	0
Average number of dihedral angle constraints violations per conformer (°)	0	0
Average r.m.s.d for ordered residuesa to the mean structure (Å)
Backbone atoms (N, Cα, C’)	0.5	0.4
All atoms	1.0	0.9
Ramachandran plot summary for ordered residuesa from PROCHECK 32
Most favoured regions	91.4 %	91.1 %
Additionally allowed regions	7.8 %	8.8 %
Generously allowed regions	0.8 %	0.1 %
Disallowed regions	0.0 %	0.0 %
PROCHECK raw scorea (φ and ψ/all dihedral angle)	−0.50/−0.75	−0.47/−0.73
PROCHECK z-scorea (φ and ψ/all dihedral angle)	−1.65/−4.44	−1.53/−4.32

^aResidues 24–34, 41–58, and 72–127 of IscU(WT) and residues 26–38, 40–62, and 68–27 of IscU(D39A) were considered ordered by the Protein Structure Validation Software Suite.²⁸