TABLE 4.

Novel dnaC mutations and their phenotypes

Mutant plasmid	Nucleotide substitution(s)	Amino acid substitution(s)	Relative plating efficiencya
			KH1061 (recA+ ΔdnaC::cat)	MF1061 (recA::Kanr ΔdnaC::cat
pACYC184dnaC	None	None	1.2	1.3
pACYC184	Not relevant	Not relevant	1.8 × 10−3	1.2 × 10−5
31-f3	G289A, T318A (silent)	Gly97Ser	1.0 × 10−3	2.6 × 10−5
157-c2	A428G	Lys143Arg	1.4 × 10−3	1.3 × 10−5
36-c4	G289A	Gly97Ser	2.1 × 10−4	1.4 × 10−5
29-d3	A534G (silent), G716T	Arg239Leu	1.6 × 10−4	2.6 × 10−5
55-c6	T425C, A521G	Met142Thr, Gln174Arg	7.7 × 10−5	9.3 × 10−6
97-h9	T129C (silent), A218G	Asn73Ser	2.0 × 10−4	2.0 × 10−5
107-g12	A40G, T178C	Met14Val, Ser60Pro	3.3 × 10−4	2.8 × 10−5
125-c1	G359A	Cys120Tyr	2.1 × 10−4	7.9 × 10−6
145-f1	T89C, A237G (silent), A394T, G565A	Leu30Pro, Ile132Phe, Asp189Asn	4.1 × 10−4	2.0 × 10−5
151-a2	T86C, A248G	Leu29Pro, Asn83Ser	2.2 × 10−4	1.7 × 10−5
239-e10	T178A, T213C (silent), A336G (silent), C504A (silent), A632G	Ser60Thr, Lys211Arg	3.1 × 10−4	1.2 × 10−5
164-g2	G82A, T207C (silent), A676T	Glu28Lys, Ser226Cys	6.0 × 10−4	1.9 × 10−5
40-g4	A71G, A107G, T189C (silent), T254A, A354T (silent), A400G, C483T (silent)	Lys24Arg, Gln36Arg, Leu85Stop, Thr134Ala	1.6 × 10−5	1.1 × 10−5
4-g1	A712T	Ser238Cys	1.2b	1.2b
38-e4	T68C, T207C (silent)	Phe23Ser	1.7b	1.2b
54-b6	A84T, T706A	Glu28Val, Tyr236Asn	1.0b	0.7b
234-h9	T358C, T686A	Cys120Arg, Val229Glu	1.4b	0.7b
35-b4	T650A	Val217Glu	6.1 × 10−6	1.8 × 10−5
246	T131C	Leu44Pro	4.6 × 10−6	2.3 × 10−5
256-f12	A451C, G659A	Thr151Pro, Arg220His	1.0 × 10−5	2.1 × 10−5

^aCultures of the indicated strains carrying pAM34dnaC and the pACYC184 derivative encoding the respective dnaC mutation(s) were serially diluted and plated as described in footnote a of Table 3, but the plating medium was additionally supplemented with chloramphenicol. Relative plating efficiency is defined in footnote a of Table 3.

^bOn medium lacking IPTG, the colonies were either heterogeneous in size or uniformly smaller (for Phe23Ser).