Table 2. Structural alignments of loop regions.

(a) Loops of apo-Tr were aligned to biotin–Tr, apo-SA and biotin–SA. Residues comprising each loop are shown in parentheses. (b) Loops of apo-SA were aligned to biotin–SA, apo-Tr and biotin–Tr. Only main-chain atoms were used to calculate the alignments. *The loop of 1SWA was compared only with the resolved residues of 45 and 49–52, since 46–48 were disordered.

(a)
	Rmsd (Å) of alignment of loop in:
Apo-Tr (chain A) aligned with	Biotin–Tr	Apo-SA (1SWA chain B)	Biotin–SA (1SWE chain D)
L1/2 (23–26)	0.050	0.20	0.21
L2/3 (33–38)	0.14	0.23	0.15
L3/4 (45–52)	0.25	2.3*	0.25
L4/5 (62–70)	0.20	0.20	0.22
L5/6 (79–88)	0.18	0.28	0.18
L6/7 (98–102)	0.14	0.22	0.37
L7/8 (113–121)	0.20	0.23	0.24
Overall structure	0.21	0.29	0.35
(b)
	Rmsd (Å) of alignment of loop in:
Apo-SA (1SWA chain B) aligned with	Biotin–SA (1SWE, chain D)	Apo-Tr (chain A)	Biotin–Tr
L1/2 (23–26)	0.27	0.20	0.18
L2/3 (33–38)	0.23	0.23	0.22
L3/4 (45–52)	2.6*	2.3*	2.3*
L4/5 (62–70)	0.25	0.20	0.25
L5/6 (79–88)	0.31	0.28	0.27
L6/7 (98–102)	0.42	0.22	0.26
L7/8 (113–121)	0.17	0.23	0.15
Overall structure	0.36	0.29	0.25