Extended Data Fig. 10: AlkG in electron transfer.

a, FtAlkG structure and its [Fe-4S] iron-sulfur cluster. The iron is shown as a red sphere and the four cysteine residues are shown as sticks. Four negatively charged residues are also shown as sticks. Cryo-EM density for the iron-sulfur cluster was shown as gray isomeshes. b, Electrostatic interactions between FtAlkB and FtAlkG. Positively charged arginine residues on AlkB and negatively charged glutamate or aspartate residues are shown as sticks. c, Electron transfer between PaAlkT and PaAlkG at a distance of 7.4 Å from FAD to the iron center. d, AlkG on and off from AlkT and AlkB for electron transfer. We superimposed the FtAlkBG structure with PaAlkG-AlkT complex. The sequence identity between FtAlkG and PaAlkG is 54.5%. The superimposition was performed on the FtAlkG and PaAlkG with an R.M.S.D. of 0.932 Å for 49 aligned Cα atoms. In the superimposed structure, AlkT and AlkB bind to the same AlkG site to transfer and receive an electron, respectively. FtAlkB, salmon; FtAlkG, green; PaAlkT, gray; PaAlkG, orange. FAD molecule in PaAlkT is drawn as sticks. The three irons in the FtAlkBG are shown as red spheres. Substrate dodecane is shown as magenta sticks.