. Author manuscript; available in PMC: 2009 Aug 3.

Published in final edited form as: J Mol Biol. 2007 Jun 9;371(5):1261–1273. doi: 10.1016/j.jmb.2007.06.011

Table 2.

Interactions between the active site residues and ligands in the R-state structures

		R_{236_P}^a	R_{236_PA}^a	R_PALA^a	R_{CP_suc}^a	R_PM^a	R_{pi_cit}^a
1^b	NH₂	Gln137	Gln137^c	N/A	Gln137	Gln137	N/A
			Pro266		Pro266	Pro266
			Leu267		Leu267
2	O^-	Thr55	Thr55	Arg105	Thr55	Thr55	Thr55
		Arg296	Arg105	His134	Arg105	Arg105	Gln137
		His134	His134		His134	His134	His134
3	ester O	N/A	N/A	N/A	Arg54	N/A	N/A
4	amide NH	N/A	Leu267	Leu267	N/A	N/A	N/A
5	α-COO^-	N/A	Arg105	Arg105	Arg167	Arg167	Arg167
			Arg167	Arg167	Lys84*		Lys84*
			Lys84*	Lys84*
6	β-COO^-	N/A	Arg229	Arg229	Arg229	Arg229	Arg229
			Gln231	Gln231	Gln231		Gln231
7	P_i	Ser52	Ser52	Ser52	Ser52	Ser52	Ser52
			Thr53	Thr53	Arg54	Arg54	Thr53
		Arg54	Arg54	Arg54	Arg105	Thr55	Arg54
		Thr55	Thr55	Thr55	Ser80*	Arg105	Thr55
			Arg105	Arg105	Lys84*	Ser80*	Arg105
			Ser80*	Ser80*			Ser80*
			Lys84*	Lys84*			Lys84*

R_{236_P}, the X-ray structure of D236A ATCase in the presence of PAM (PDB code:2A0F); R_{236_PA}, the X-ray structure of D236A ATCase in the presence of PAM and Asp (PDB code:2HSE); R_PALA, the X-ray structure of wild-type ATCase in the presence of PALA (PDB code: 1D09²⁵); R_{CP_suc}, the X-ray structure of wild-type ATCase in the presence of CP and succinate¹⁸; R_PM, the X-ray structure of wild-type ATCase in the presence of PAM and malonate (PDB code: 2AT1)¹⁹; R_{pi_cit}, the X-ray structure of wild-type ATCase in the presence of phosphate and citrate (PDB code:1R0B)²⁴. Inline graphic

Number refers to the numbering of the reaction intermediate.

Italics indicates that the interaction is observed in only one of the two catalytic chains in the asymmetric unit.