3As Energy and carbon metabolism Calvin Cycle rbcL Ribulose-1,5-bisphosphate carboxylase/oxygenase large subunit + –     cbbFC1 Fructose-1,6-bisphosphatase + 0     cbbA1 Fructose biphosphate aldolase 0 –   TCA cycle/reductive carboxylate cycle icd Isocitrate dehydrogenase, specific for NADP+

+ 0   Glyoxylate and dicarboxylate metabolism aceB Malate synthase A + 0     gltA Citrate CX-4945 purchase synthase + 0     aceA Isocitrate lyase 0 +     / Tartrate dehydrogenase/decarboxylase (TDH) (D-malate dehydrogenase [decarboxylating]) 0 +   Glycolyse/gluconeogenesis ppsA Phosphoenolpyruvate synthase + –     aceE Pyruvate dehydrogenase E1 component + –     lpdA Dihydrolipoyl dehydrogenase (Pyruvate MM-102 purchase dehydrogenase E3 component) + 0     eno2 Enolase 0 –   Thiosulfate oxydation / Putative sulfur oxidation protein SoxB 0 – Cellular processes, transport

and binding proteins Arsenic resistance arsA2 Arsenical pump-driving ATPase + 0     arsC1 Arsenate reductase 0 +   High temperature resistance hldD ADP-L-glycero-D-manno-heptose-6-epimerase + 0   General stress groL GroEL, 60 kDa chaperonin + 0   Other stresses ahpF Alkyl hydroperoxide reductase subunit F 0 –   Twitching/motility/secretion / Putative methyl-accepting chemotaxis protein 0 –     / Putative type IV pilus assembly protein PilM 0 –   Cell division / Putative cell division protein 0 – DNA metabolism, transcription and protein synthesis DNA bending, supercoiling, inversion gyrA DNA gyrase subunit A + –   RNA degradation pnp Polyribonucleotide nucleotidyltransferase + –   Protein synthesis fusA Elongation factor G (EF-G) + 0     tufA Elongation factor Tu + 0     rpsB 30S ribosomal protein S2 + 0     rpsA 30S ribosomal protein S1 0 – a + and -: these proteins are more or less abundant

in the presence of As(III), respectively. 0: no difference observed (for details, see Additional File1). Figure 3 Differential proteomic analysis in T. arsenivorans and Thiomonas sp. 3As strains, in Dichloromethane dehalogenase response to As(III). On the gel presented are extracts obtained from (A) T. arsenivorans or (B)Thiomonas sp. 3As cultivated in the absence (left) or in the presence (right) of 2.7 mM As(III). Spots that are circled showed significant differences of accumulation pattern when the two growth conditions were compared. Protein sizes were evaluated by comparison with protein size standards (BenchMark™ Protein Ladder, Invitrogen). The expression of several proteins involved in other metabolic pathways changed, suggesting that in the presence of arsenic, the general metabolism of T. arsenivorans and 3As was modified. Indeed, enzymes involved in glyoxylate metabolism were more abundant in the presence of arsenic, suggesting that expression of such proteins is regulated in response to arsenic in both strains. However, several changes observed were clearly different between both strains. In T.