Table 1.

Agreement between K27-Ub₂ structures and NMR data

Structure or Conformational Ensemble	Data a	rb	Qc
RDC, aligned tensors d	RDC-SVD	0.98	0.11
RDC, angle-optimized e	RDC-SVD	0.99	0.10
15N Relaxation, angle-optimized e	RDC-SVD	0.95	0.22
15N Relaxation, aligned tensors d	Relaxation	0.90	0.31
15N Relaxation, angle-optimized e	Relaxation	0.91	0.29
SES, 1-conformer ensemble	RDC-SVD	0.98	0.12
SES, 1-conformer ensemble	Pred-RDC	0.97	0.16
SES, 2-conformer ensemble	Pred-RDC	0.99	0.07

^aFor RDC-SVD, the agreement is calculated between experimental RDCs and RDCs back-calculated from NH vectors using SVD. For Pred-RDC, the agreement is calculated between experimental RDCs and RDCs predicted directly from structure using PATI(Berlin et al., 2009).

^bPearson’s correlation coefficient.

^cQuality factor for RDCs (Clore and Garrett, 1999) or ¹⁵N relaxation data (Ghose et al., 2001). Lower Q means better agreement.

^dStructures labeled ‘aligned tensors’ were obtained by orienting the two Ubs such that the corresponding axes of the alignment tensors (RDC) or diffusion tensors (¹⁵N relaxation) reported by each Ub analyzed separately were parallel to each other (Fushman et al., 2004).

^eStructures labeled ‘angle-optimized’ were generated using ELMDOCK (Berlin et al., 2011) (for ¹⁵N relaxation data) or PATIDOCK (Berlin et al., 2010) (for RDC data) to obtain the best agreement between the experimental and predicted relaxation or RDC data for both Ubs taken together.