Table 2. Structure alignment of BvHSS subunit A to subunit B:

	Subunit B to A [Å2] (residues 3-476 , super)	Subunit B to A [Å2] (residues 3-476 , rms_cur)	“Track-and-trace” loop, subunit B to A [Å2] (residues 120-130, rms_cur)	Subunit B to A [Å2] (NAD(H), rms_cur)
BvHSS w/o substrate; PDB ID: 4PLP	0.15 (2786 atoms)	0.81 (3699 atoms)	1.72 (93 atoms)	0.58 (44 atoms)
BvHSS with DAP (co-cryst.), PUT (soak); PDB ID: 4TVB	0.13 (2853 atoms)	0.68 (3699 atoms)	0.57 (93 atoms)	0.57 (44 atoms)

Aligned with the “super” algorithm as implemented in the program PyMOL (5 cycles) to align subunit B residues 3-476 (complete residue without hydrogens, always using alternate location A) to chain A of respective BvHSS structure; all other RMSD values were calculated with the rms_cur function as implemented in the program PyMOL for complete residues without hydrogens, always using alternate location A. The respective residue range and the used alignment method are given in round parenthesis in the first row of the table. The number of atoms of the aligned parts of both molecules used to calculate each RMSD is given in parenthesis.