Table 1. Structure statistics for the 10 final refined structures of [d(CGC)r(aaa)d(TTTGCG)]₂.

NOE restraints			530
	intranucleotidea		288
	sequentiala		146
	cross-strand		6
	involving exchangeable protonsb		90
Torsion angle restraintsc			208
Hydrogen bond restraints			30
Relaxation matrix refinement
	number of peak integrals used at each mixing timed		248
	average R1/6 factor		0.0266 ± 0.0003
Refinement statistics (10 final lowest-energy structures)
	NOE violation >0.5 Å		<2
	dihedral angle violation >5°		0
	average pairwise r.m.s.d.
		all heavy atom	1.25 ± 0.36
		without 5′ and 3′ terminus	0.81 ± 0.26
		hybrid segmente	0.43 ± 0.08
	average r.m.s.d. from ideal covalent geometry
		bond lengths (Å)	0.0085 ± 0.0001
		bond angles (˚)	3.31 ± 0.12
		impropers (˚)	0.34 ± 0.01

^aThe NOE restraints were for the two degenerate strands.

^bTwenty-two imino proton to non-exchangeable proton NOEs, 20 amino proton to exchangeable proton NOEs, 18 imino and amino proton NOEs, and 30 C2′-hydroxyl proton to non-exchangeable proton NOEs.

^cSee Materials and Methods.

^dCross-peak volumes were measured in three NOESY spectra with mixing times of 60, 120 and 240 ms. Number of peaks were for the two degenerate strands.

^eHybrid segment is defined as 4a to 6T, i.e. [r(aaa)d(TTT)]₂.