Fig. 4: CysG variants respond differently to cobalt challenge.

a ANOVA pairwise comparison in a two-tailed test of CysG-deficient E. coli expressing each variant (n = 18, CysG; = 37, D104N; = 21, P133G; = 25, P133H; = 18, R260A; = 18, R261A, = 15, D262N) was used to show which were statistically impacted by growth on M9 media. All were different than one another with a p value of < 0.001 (see Supplementary Table 1 for details) except those marked here. “*”≤ 0.5 and statistically indistinguishable. There was a significant effect of the CysG variant with an F value of 168.5 and 6 degrees of freedom. Error bars show standard deviations. b ANCOVA analysis of the impact of increasing cobalt concentration on colony size for CysG-deficient E. coli expressing each variant, interpreted as the slope of the line shown in each graph, followed by ANOVA analysis of the slopes to assess whether each variant was affected in a similar or different way. There was a significant interaction between each CysG variant and cobalt concentration with an F value of 43.1 and 6 degrees of freedom (number of colonies counted for each Co²⁺ concentration provided in Supplementary Table 2). Three groups arose: those that were affected like CysG (D104N and R261A), those that were dramatically affected (P133G and D262N), and those that were more modestly affected (P133H and R260A). Error bars show standard deviations. Source Data are provided as Source Data File SourceData_co-competition.txt.