Summary of the 42 proteins identified by mass spectrometry. The molecular weight (MW) and isoelectric point (pI) values determined by 2DE vs. theoretical are presented for comparison.

Protein spot	Abundance in irradiated E. coli [fold-change (p-valuea)]	Protein ID	Accession	Coverage (%)	No. of unique peptides	Theoretical MW [kDa]/pI	Calculatedb MW [kDa]/pI	Sequest score
1	↓1.3 (0.004)	Aconitate hydratase B	P36683	44	38	93.4/5.4	83.4/4.9	846.66
		Pyruvate dehydrogenase E1 component	P0AFG8	25	22	99.6/5.7		85.02
		Aldehyde–alcohol dehydrogenase	P0A9Q7	17	12	96.1/6.8		71.4
		2-Oxoglutarate dehydrogenase E1 component	P0AFG3	12	9	105/6.5		23.09
		NADH-quinone oxidoreductase subunit G	P33602	9	9	100.2/6.3		22.31
		Leucine-tRNA ligase	P07813	9	7	97.2/5.3		17.1
		Elongation factor G	P0A6M8	8	4	77.5/5.4		9.61
		DNA mismatch repair protein MutS	P23909	3	2	95.2/5.55		4.3
		DNA gyrase subunit A	P0AES4	2	2	96.9/5.2		4.22
2	↑3.0 (<0.001)	GTP-binding protein TypA/BipA	P32132	13	6	67.3/5.3	73.4/4.8	5.33
		Catalase-peroxidase	P13029	8	5	80/5.3		5.31
		Formate acetyltransferase 1	P09373	4	3	85.3/6.0		6.01
		Polyribonucleotide nucleotidyltransferase	P05055	3	2	77.1/5.2		5.21
3	↑2.0 (<0.001)	Formate acetyltransferase 1	P09373	16	11	85.3/6.0	72.7/5.3	6.01
		Phosphoenolpyruvate-dependent phosphotransferase system	P37177	3	2	83.7/5.8		5.78
4	↑1.6 (<0.001)	Exoribonuclease 2	P30850	14	7	72.4/5.6	70.6/5.2	5.62
		Chaperone protein ClpB	P63284	7	5	95.5/5.5		5.52
		Dihydrolipoyllysine-residue acetyltransferase component of pyruvate dehydrogenase complex	P06959	5	3	66.1/5.2		5.17
		Glycine-tRNA ligase beta subunit	P00961	2	2	76.8/5.4		5.44
		Bifunctional polymyxin resistance protein ArnA	P77398	3	2	74.2/6.9		6.87
5	↑1.4 (0.001)	Chaperone protein HtpG	P0A6Z3	49	33	71.4/5.2	67.7/4.7	5.21
		Lysine-tRNA ligase, heat inducible	P0A8N5	26	12	57.8/5.2		5.24
		Dihydrolipoyllysine-residue acetyltransferase component of pyruvate dehydrogenase complex	P06959	14	7	66.1/5.2		5.17
		Proline-tRNA ligase	P16659	8	4	63.7/5.2		5.24
		30S ribosomal protein S1	P0AG67	6	4	61.1/5.0		4.98
		Polyribonucleotide nucleotidyltransferase	P05055	3	2	77.1/5.2		5.21
		Methionine-tRNA ligase	P00959	3	2	76.2/5.9		5.86
6	↓1.5 (<0.001)	d-Tagatose-1,6-bisphosphate aldolase subunit GatZ	P0C8J8	18	7	47.1/5.8	53.7/5.2	5.77
		Periplasmic pH-dependent serine endoprotease DegQ	P39099	8	3	47.2/6.0		5.95
		Dihydrofolate synthase/folylpolyglutamate synthase	P08192	5	2	45.4/5.8		5.8
		Xaa-Pro aminopeptidase	P15034	6	2	49.8/5.4		5.39
		Bifunctional protein HldE	P76658	5	2	51.0/5.4		5.41
7	↑1.5 (0.006)	NADH-quinone oxidoreductase subunit F	P31979	12	5	49.3/6.9	49.9/6.6	6.86
8	↑1.9 (<0.001)	Aspartate aminotransferase	P00509	17	7	43.5/5.8	43.3/5.3	5.77
		NADPH-dependent curcumin reductase	P76113	7	2	37.6/5.8		5.82
		Aminomethyltransferase	P27248	5	2	40.1/5.6		5.57
		Maltose-binding periplasmic protein	P0AEX9	6	2	43.4/5.7		5.71
		Fructose-bisphosphate aldolase class 2	P0AB71	6	2	39.1/5.9		5.86
9	↓1.5 (0.006)	DNA protection during starvation protein	P0ABT2	50	12	18.7/6.1	16.9/5.6	6.11
		50S ribosomal protein L13	P0AA10	10	2	16.0/9.9		9.91
10	↑1.4 (0.011)	10 kDa chaperonin	P0A6F9	65	6	10.4/5.2	13.4/4.9	5.24
		30S ribosomal protein S6	P02358	13	2	15.7/5.0		5

^aSignificantly different from control, as displayed in the Delta2D quantitation table (Student’s t-test).

^bCalculated in Delta2D, calibrated with Bio-Rad 2-D PAGE standards.