Table 3. Distances between atoms at the tetrameric interfaces.

	Structure A (PDB code 2f97)	Structure B (PDB code 2f8d)
Interaction†	Distance‡ ()	Distance, A subunit§ ()	Distance, B subunit§ ()
Lys148NAsp213O	3.50	2.90	3.73
Lys148OGly215N	3.23	[4.08]	3.55
Lys148NZAsp264OD2	3.01	3.5	3.87
Ser150NHis214O	3.21	[4.59]	3.35
Ser150OGLeu184N	3.49	3.28	3.52
Ser150OGAsp262OD1	2.66	2.83	2.61
Ser150OGAsn185N	3.16	3.11	3.17
Arg156NH2Asp264OD1	4.67 ¶	2.84	3.91 ¶
Asn209OD1Ser212OG	2.69	4.05	2.83

^†In addition to the interactions listed, there are symmetry-related interactions generated by the crystallographic twofold that bisects the interface.

^‡Not all distances presented are suggested to be ionic or hydrogen bonds. In some cases, the distance between the atoms is provided in order for comparison with its equivalent counterpart in the other structure. Distances greater than 3.4 are italicized. Bracketed distances do not represent contacting atoms.

^§The A subunit contains a molecule of benzoate in the primary effector-binding site. Both subunits have benzoate molecules in the secondary effector-binding sites. The A subunit interacts with a symmetry-related (x,y,z + 1/2) A subunit at the tetramerization interface, while the B subunit interacts with a symmetry-related (x, y,z) B subunit.

^¶A water molecule bridges these atoms.