Reactions constituting cluster 44 and nearby clusters from wild-type and lpdA mutant of E. coli . Clusters 21, 24, 26, 29, 31, 32, 34 and 40 are under direct influence of cluster 44. Each box contains information on reactions in the order of their respective TMI values for each cluster (see Additional file 1 for details). Numbers next to each cluster number are the calculated average essentiality of reactions in the cluster for the wild-type and lpdA mutant in order; the higher the essentiality value is, the more essential the reaction is. Reactions in red are the representative reactions. Parenthesis next to the enzyme name shows the name of submetabolism, in which the enzyme is involved. To differentiate two transketolases in cluster 44, their corresponding reactions are shown next to the enzyme name. Cluster 43 influencing cluster 44 contains three reactions: 4-aminobutyrate transaminase (arginine and proline Metabolism), glutamate decarboxylase (glutamate metabolism), and isocitrate dehydrogenase (TCA cycle). Abbreviations are: e4p, D-erythrose 4-phosphate; r5p, alpha-D-ribose 5-phosphate; f6p, D-fructose 6-phosphate; g3p, glyceraldehyde 3-phosphate; s7p, sedoheptulose 7-phosphate; xu5p-D, D-xylulose 5-phosphate.