Table 2.

Chain Interfaces Calculated by PISA^a

interface	chain 1:chain 2	residues	area (Å2)	H-bonds	salt bonds	CSSc	color
1	dho1(A):dho4(G)	30:30	1082	10	26	0.969	purple
2	atc1(B):atc2(D)	26:26	946	19	8	1.00	blue
(2)	atc1(B):atc3(F)	26:26	946	19	8	1.00	cyan
3	atc1(B):dho1(A)	23:22	788	9	7	0.427	green
4	atc1(B):dho4(G)	20:22	768	12	0	0.191	yellow
5	dho1(A):dho5(I)	12:12	389	2	0	0.059	orange
6	dho1(A):atc3(F)	4:5	51	2	0	0.018	red
7b	atc1(B):atc*	11:11	114	10	10	0.00	gray

^aThe Protein Interfaces, Surfaces, and Assemblies service (PISA) at the European Bioinformatics Institute (http://www.ebi.ac.uk/msd-srv/prot_int/pistart.html) identified six protein interfaces in the DAC dodecamer and one packing contact in the crystal. The six interfaces within the dodecamer are ranked in decreasing order of their buried surface area, which is an approximate measure of the strength of the interaction, and correspondingly colored in descending order of spectral energy (59). The crystal packing contact is colored gray.

^bCrystal packing contact between two dodecamers in the crystal.

^cComplexation significance score.