Table 2.

Enzymes of Escherichia coli, Salmonella typhimurium and Bacillus subtilis that are involved in the biosynthetic pathway for each amino acid.

		Gene			Specific activity (μM min-1 mg-1)			Molecular activity (Mol reactant s-1 Mol enzyme-1)
Amino Acid	EC number	E. coli	S. typhimurium	B. subtilis	E. coli	S. typhimurium	B. subtilis	E. coli	S. typhimurium	B. subtilis
Alanine	2.6.1.66	avtA	avtA	–	0.0196	0.0196	–	0.0151	0.0152	–
	2.6.1.42	ilvE	ilvE	ywaA	15.9	15.9	15.9	9.05	9.02	10.7
	5.1.1.1	alr	alr	alr, yncD	133	910	143	–	0.130	103
Arginine	2.3.1.1	argA	argA	argA	133	133	133	109	109	96.1
	2.7.2.8	argB	argB	argB	0.540	0.540	0.540	0.244	0.243	0.249
	1.2.1.38	argC	argC	argC	0.950	0.950	0.950	0.569	0.569	0.603
	2.6.1.11	argD	argD	argD	11.2	11.2	11.2	8.17	8.15	7.63
	3.5.1.16	argE	argE	amhX	800	800	800	564	562	567
	2.1.3.3	argF	–	argF	2900	–	265	1780	–	153
	2.1.3.3	argI	argI	–	2900	1900	–	1780	1160	–
	6.3.4.5	argG	argG	argG	12.8	12.8	4.54	10.6	11.1	3.39
	4.3.2.1	argH	argH	argH	0.380	0.380	0.380	0.319	0.320	0.329
Asparagine	6.3.5.4	asnB	asnB	asnB, asnH, asnO	0.300	0.300	0.300	0.313	0.313	0.353
	6.3.1.1	asnA	asnA	–	57.3	57.3	–	35.0	35.1	–
	3.5.1.1	iaaA, ybik	iaaA, ybik	ansA	–	–	32.0	–	–	19.4
Aspartate	2.6.1.1	aspC	aspC	aspB	232	232	220	168	168	158
	4.3.1.1	aspA	aspA	ansB	167	167	320	150	145	19.4
	6.3.5.4	–	–	asnO, asnH, asnB	–	–	0.300	–	–	0.353
	3.5.1.1	–	–	ansA	–	–	32.0	–	–	19.4
Cysteine	2.5.1.47	cysK; cysM	cysK; cysM	cysK, yrhA, ytkP	6.30	1100	25.5	3.62	398	13.9
	2.3.1.30	cysE	cysE	cysE	71.6	397	71.6	35.0	194	28.8
Glutamine	6.3.1.2	glnA	glnA	glnA	153	231	153	132	187	128
	6.3.5.5	carAB	carAB	–	4.16	4.16	–	1.20	0.890	–
	3.5.1.12	–	–	ylaM, ybgJ	–	–	716	–	–	406
Glutamate	1.4.1.13	gltBD	gltBD	gltAB	18.6	18.6	23.0	72.8	8.32	12.4
	1.4.1.4	gdhA	gdhA	–	250	231	–	202	187	–
	1.4.1.2	–	–	rocG	–	–	80.0	–	–	62.2
Glycine	2.1.2.1	glyA	glyA	glyA	13.6	13.6	13.6	10.3	10.3	10.3
Histidine	2.4.2.17	hisG	hisG	hisG	544	544	544	302	301	214
	3.6.1.31-3.5.4.19	hisI	hisI	hisI	0.00300	0.00300	332	0.00114	0.00113	132
	5.3.1.16	hisA	hisA	hisA	7.80	7.80	7.80	3.40	3.39	3.45
	2.4.2.-	hisHF	hisHF	hisFH	0.900	0.900	0.900	0.325	0.0523	0.0506
	4.2.1.19-3.1.3.15	hisB	hisB	hisB	5.70	202000	0.310	3.84	135000	0.111
	2.6.1.9	hisC	hisC	hisC	1890	1890	325	1240	1250	217
	3.1.3.15	–	–	hisJ	–	–	427	–	–	217
	1.1.1.23	hisD	hisD	hisD	15.3	14.3	3.60	11.8	10.9	2.77
Isoleucine	1.2.4.1	–	–	acoAB, pdhAB	–	–	0.120	–	–	0.00567
	4.3.1.19	ilvA	ilvA	–	230	683	–	215	640	–
	2.2.1.6	ilvGM; ilvBN; ilvIH	ilvGM; ilvBN; ilvIH	ilvBN	4000	4000	4000	500	456	812
	1.1.1.86	ilvC	ilvC	ilvC	1.90	1.91	1.91	1.71	1.72	1.19
	4.2.1.9	ilvD	ilvD	ilvD	63.0	63.0	63.0	67.6	35.7	62.5
	2.6.1.42	ilvE	ilvE	ilvE	27.3	27.3	27.3	15.5	4.34	18.3
Leucine	2.3.3.13	leuA	leuA	leuA	14.5	14.7	7.10	13.8	14.1	6.73
	4.2.1.33	leuCD	leuCD	leuCD	0.072	0.0720	6.18	0.00800	0.00527	0.985
	1.1.1.85	leuB	leuB	leuB	0.085	35.5	10.5	0.0561	35.5	6.99
	2.6.1.42	ilvE	ilvE	ybgE	57.0	53.4	27.3	32.5	53.4	18.0
	1.4.1.9	–	–	bcd	–	–	110	–	–	73.3
Lysine	2.7.2.4	lysC	lysC	lysC	5.69	5.69	30.0	4.60	4.61	21.8
	1.2.1.11	asd	asd	asd	145	145	73.0	96.7	97.0	46.0
	4.2.1.52	dapA	dapA	dapA	100	100	458	52.1	52.1	237
	1.3.1.26	dapB	dapB	dapB	398	398	56.4	191	191	27.7
	2.3.1.117	dapD	dapD	dapD	36.0	36.0	36.0	17.9	17.9	15.0
	2.6.1.17	dapC; yfdZ	dapC; yfdZ	yugH	5.33	5.33	5.33	4.10	4.10	3.76
	3.5.1.18	dapE	dapE	ytjP	3.33	3.33	3.33	2.31	2.31	1.99
	5.1.1.7	dapF	dapF	dapF	18.7	18.7	18.7	9.45	9.49	9.62
	4.1.1.20	lysA	lysA	lysA	7.50	7.50	28.3	5.77	5.75	22.9
Methionine	2.3.1.46	metA	metA	metB	–	–	–	–	–	–
	2.5.1.48	metB	metB	yjcI	10.0	18.2	10.0	6.92	12.6	6.95
	4.4.1.8	metC	metC	yjcJ	248	7.90	7.90	179	5.64	5.59
	2.1.1.13	metH	metH	–	9.30	9.30	–	21.1	21.6	–
	2.1.1.14	metE	metE	metC	2.50	2.50	0.240	3.53	3.53	0.347
	2.1.1.10	–	–	ybgG	–	–	1.37	–	–	0.793
Phenylalanine	5.4.99.5-4.2.1.51	pheA	pheA	pheA, aroA, aroH	52.0	32.0	17.5	37.3	22.8	4.23
	2.6.1.57	tyrB	tyrB	–	170	170	–	123	123	–
	2.6.1.9	–	–	aroJ	–	–	323	–	–	216
Proline	2.7.2.11	proB	proB	proJ, proB	12.7	12.7	12.7	8.25	8.27	8.52
	1.2.1.41	proA	proA	proA	28.2	28.2	28.2	21.0	21.0	21.3
	1.5.1.2	proC	proC	proGH	2550	2550	280	1200	1190	141
Serine	1.1.1.95	serA	serA	serA	9.70	9.70	15.6	7.14	7.11	14.8
	2.6.1.52	serC	serC	serC	15.0	15.0	15.0	9.94	9.95	10.0
	3.1.3.3	serB	serB	rsbP	3.00	3.00	3.00	1.75	1.75	2.300
Threonine	2.7.2.4-1.1.1.3	thrA	thrA	lysC, dapG, yclM	5.69	5.69	30.0	8.45	8.41	21.5
	1.2.1.11	asd	asd	asd	145	145	0.0400	97.0	97.0	0.0252
	1.1.1.3	–	–	hom	–	–	51.0	–	–	40.3
	2.7.1.39	thrB	thrB	thrB	3.10	3.10	3.10	1.74	1.72	1.72
	4.2.3.1	thrC	thrC	thrC	7.70	7.70	8.80	6.04	6.03	5.49
Tryptophan	4.1.3.27	trpDE	trpDE	trpE	2.60	0.380	0.380	1.30	0.0457	0.368
	2.4.2.18	trpD	trpD	trpD	177	–	1.58	2.46	–	0.948
	5.3.1.24-4.1.1.48	trpC	trpC	trpF	8.78	2.30	8.78	7.24	1.89	3.52
	4.1.1.48	–	–	trpC	–	–	3.70	–	–	1.72
	4.2.1.20	trpAB	trpAB	trpAB	125	125	2.80	20.0	39.7	1.07
Tyrosine	5.4.99.5-1.3.1.12	tyrA	tyrA	aroA, aroH, pheA	52.0	52.0	17.5	36.4	36.3	4.23
	2.6.1.57	tyrB	tyrB	aroJ	70.2	70.2	323	50.9	50.9	216
Valine	1.2.4.1	–	–	acoAB, pdhAB	–	–	0.120	–	–	0.00567
	4.3.1.19	ilvA	ilvA	–	230	683	–	215	640	–
	2.2.1.6	ilvGM; ilvBN; ilvIH	ilvGM; ilvBN; ilvIH	ilvBN	4000	4000	4000	500	456	812
	1.1.1.86	ilvC	ilvC	ilvC	1.90	1.91	1.91	1.71	1.72	1.19
	4.2.1.9	ilvD	ilvD	ilvD	63.0	63.0	63.0	67.6	35.7	62.5
	2.6.1.42	ilvE	ilvE	ilvE	27.3	27.3	27.3	15.5	4.34	18.3
	2.6.1.66	avtA	avtA	–	0.0196	0.0196	–	0.0151	0.0152	–

For each amino acid, italicized type indicates the gene for the enzyme in its classical biosynthetic pathway. Bold italicized type indicates an auxiliary enzyme that has been observed to replace an enzyme in the classical pathway, at least in vitro, but that is not usually considered part of the biosynthetic pathway. We were unable to find appropriate estimates for the activity of enzyme 2.3.1.46 in methionine biosynthesis.