Table 1.

Statistics of NMR restraints guided computations of the FMRP RGG peptide-RNA complex.

	Peptide	RNA
NMR distance and dihedral constraints
Distance restraints
Total NOE	58	232
Inter-residue
Sequential (|i – j| = 1)	40	126
Non-sequential (|i – j| > 1 )	18	106
Hydrogen bonds	8	67
Peptide–RNA intermolecular	90
Total dihedral angle restraints	9	226
Protein
φ	10 a
ψ
RNA
Sugar pucker		35 b
Backbone		71 c
Based on A-form geometry		120 d
Structure statistics
Violations (mean and s.d.)	1.0±0.0	1.0±0.0
Max. distance constraint violation (Å)	0.324	0.201
Deviations from idealized geometry
Bond lengths (Å)	0.01±0.00	0.01±0.00
Bond angles (°)	0.75±0.01	0.75±0.01
Impropers (°)	0.49±0.01	0.49±0.01
Average pairwise r.m.s. deviation (Å)
Pairwise r.m.s. deviation was calculated among 10 refined structures
Peptide
All backbone heavy atoms	1.32±0.34
Backbone heavy atoms, residues 7–17	0.64±0.12
RNA
All RNA heavy except residues 10,13,14,19,22,23,27		1.01±0.11
Complex
Peptide residues 7–17 & all RNA except residues 10,13,14,19,22,23,27	1.14±0.12

^aThe φ values for peptide residues D6, R8, R9, R10, R15, Q17, R20, R22, F26 and K27 were restrained in the −30° > φ> −75 °range, based on the observed H^N-H^α vicinal J-couplings (< 5 Hz).

^bPseudoration angles for RNA residues 6, 9, 10–13, 15–24, 26–28 were restrained to the C2´-endo domain; those for the residues 1–5, 7–8, 11, 14, 25, 29–36 were restrained to the C3´-endo domain, identified experimentally.

^cNucleotide residues were restrained to χ values in the 195 (±50)° range, characteristic of anti glycosidic RNA torsion values, and ε were restrained to the stereochemically allowed range of 200 (±50)°.

^dα, β, γ, ζ angles of the duplex part of RNA were restrained to values characteristic for A-RNA: 298 (±70)°, 180 (±70)° 315(±15)°, 285 (±70)° correspondingly.

A-form RNA restraints for sugar-phosphate backbone of standard RNA duplex (residues 1–5 and 30–35) were switched off at the final minimization stages.