Table 5.

Nearest neighbors frequencies at sites of spontaneous, ionizing radiation-, or oxidation-induced G → T transversions in the lacI gene of E. coli

Nearest neighbors distribution at G → T transversion sites in E. coli lacI
Sequence context	Total number of mutations (n = 147)				Number of mutated sites (n = 36)
	O	E	χ2	P	O	E	χ2	P
5′-N(G → T)A-3′	100	37	109	<0.001	19	9	11	<0.001
5′-G(G → T)A-3′	42	9	117	<0.001	7	2	10	<0.005
5′-C(G → T)C-3′	11	9	0.4	<0.5	2	2	0	0
5′-T(G → T)T-3′	2	9	5.6	<0.01	1	2	0.7	<0.25

Nearest neighbors distribution at G sites in E. coli lacI(n = 362)
					O	E	χ2	P
5′-N(G)A-3′					68	91	5.6	<0.025
5′-G(G)A-3′					19	23	0.6	<0.25
5′-C(G)C-3′					38	23	10.45	<0.005
5′-T(G)T-3′					19	23	0.6	<0.25