Journal: Synthetic and Systems Biotechnology
Article Title: Reconstructing the hydrogenobyrinic acid synthetic toolkit by combining cell-free systems and metabolic engineering
doi: 10.1016/j.synbio.2026.01.012
Figure Lengend Snippet: Screening of bottleneck reaction steps in the 1w–SmHBA operon by multienzyme catalysis. a, Schematic illustration of the reaction components. The in vitro reaction system consisted of crude cell extracts (CCE) from strains harboring the 1w–SmHBA plasmid as the basic catalytic source, supplemented with multienzyme-expressing strains carrying plasmids encoding 4–5, 2–3, or single heterologously expressed Cob enzymes to alter the enzyme composition in each reaction. b, Comparison of in vitro HBA production using CCE from strains H1, H2, and LvH0. Two-sided unpaired t -test is carried out between H1, H2, and LvH0. Unpaired t -test of data: H1 to H2, ∗∗∗∗, P < 0.0001 (t = 35.12); LvH0 to H2, ∗∗∗∗, P < 0.0001 (t = 30.84). c, In vitro HBA production using CCE from H21–H28 strains, each harboring an additional RcCob enzyme. Red bars indicate values higher than those of the H2 reactant, whereas blue bars indicate values lower than those of H2 reactant. Two-sided unpaired t -test is carried out between H1 to H21-28. Unpaired t -test of data:H2 to H21, ∗, P = 0.0227 (t = 3.605); H24 to H2, ∗∗∗∗, P < 0.0001 (t = 24.60); H27 to H2, ∗, P = 0.5363 (t = 0.6757). d, In vitro HBA production using CCE from H37–H44 strains, in which SmCob enzymes were replaced with the corresponding RcCob enzymes. Two-sided unpaired t -test is carried out between H1 to H37-44. Unpaired t -test of data:H37 to H2, ∗, P = 0.0145 (t = 4.129); H41 to H2, ∗, P = 0.0315 (t = 3.246); H42 to H2, ∗∗∗, P = 0.0003 (t = 11.66); H43 to H2, ∗, P = 0.0229 (t = 3.592); H44 to H2, ∗∗∗∗, P < 0.0001 (t = 15.76). e, Screening of reactions supplemented with crude cell extracts from strains heterologously expressing 4–5 Cob enzymes. HBA-A: CCE with pET28a–CobAIGJM; HBA-B: CCE with pACYCDuet-1–CobFKLH. Unpaired t -test of data: HBA-A 45 OD 600 to Control in HBA titer, ns, P = 0.0729 (t = 2.418); HBA-B 45 OD 600 to Control in HBA titer, ∗∗, P = 0.0029 (t = 6.502); HBA-A 45 OD 600 to Control in Urogen III titer, ∗∗, P = 0.0022 (t = 7.002); HBA-B 45 OD 600 to Control in Urogen III titer, ∗∗, P = 0.0011 (t = 8.309); f, Screening of reactions supplemented with crude cell extracts from strains heterologously expressing 2–3 Cob enzymes. AIG: CCE with pet28a-CobAIG; JM: CCE with pet28a-CobJM; FK: CCE with pet28a-CobFK; LH: CCE with pet28a-CobLH. Unpaired t -test of data: AIG 30 OD600 to Control in Urogen III titer, ∗∗∗, P = 0.0009 (t = 8.801); JM 30 OD600 to Control in Urogen III titer, ∗∗∗∗, P < 0.0001 (t = 24.39); FK 30 OD600 to Control in Urogen III titer, ∗, P = 0.0304 (t = 3.285); LH 30 OD600 to Control in Urogen III titer, ∗∗∗∗, P < 0.0001 (t = 15.93); g, Screening of reactions supplemented with CCE from strains heterologously expressing a single Cob enzyme. Unpaired t -test of data: CobA + to ori, ∗∗∗, P = 0.0002 (t = 13.95); CobI + to ori, ∗∗∗, P = 0.0005 (t = 10.57); CobG + to ori, ∗∗∗, P = 0.0003 (t = 12.00); CobJ + to ori, ∗∗∗, P = 0.0001 (t = 15.48); CobM + to ori, ∗∗∗, P = 0.0005 (t = 10.46); CobF + to ori, ∗∗∗∗, P < 0.0001 (t = 16.42); CobK + to ori, ∗∗∗, P = 0.0006 (t = 9.873); CobL + to ori, ∗∗, P = 0.0042 (t = 5.882); CobH + to ori, ∗∗∗, P = 0.001 (t = 8.675).
Article Snippet: Supplementation of HBA-A or HBA-B CCE into a basic H2-derived HBA reaction system at gradient concentrations revealed that addition of HBA-B (downstream enzymes) significantly increased HBA titer by 17.1 ± 3.2 % and reduced Urogen III accumulation by 70.0 ± 10.8 %, while supplementation with HBA-A CCE (upstream enzymes) increased HBA titers by 12.8 ± 8.6 % and reduced Urogen III accumulation by 56.6 ± 10.0 % ( e).
Techniques: In Vitro, Plasmid Preparation, Expressing, Comparison, Control
