Table 7. Comparison of interactions within interfaces of bacterial PDC structures in order of decreasing thermostability.

Interactions were determined using PISA. Neighbour, interactions between neighbouring monomers; diagonal, interactions between monomers diagonally across tetrameric centre.

	ZpPDC (PDB entry 5euj)		ApPDC (PDB entry 2vbi)		ZmPDC (PDB entry 1zpd)		GdPDC (PDB entry 4cok)
	Hydrogen bonds	Salt bridges	Hydrogen bonds	Salt bridges	Hydrogen bonds	Salt bridges	Hydrogen bonds	Salt bridges
Dimer interface	73	12	61	16	76 (66†)	14 (7†)	63	13
Major tetramer interface (neighbour)	31	24	34	14	29 (64†)	8 (25†)	17	9
Minor tetramer interface (diagonal)	2	0	4	0	6	2	4	3
TPP pyrimidine ring	11	0	10	0	12	0	10	0

^†Dobritzsch et al. (1998 ▸).