Supplemental Information from Structure of F<sub>1</sub>-ATPase from the obligate anaerobe <i>Fusobacterium nucleatum</i> PetriJessica NakataniYoshio MontgomeryMartin G. FergusonScott A. AragãoDavid G. W. LeslieAndrew HeikalAdam WalkerJohn E. M. CookGregory 2019 The crystal structure of the F<sub>1</sub>-catalytic domain of the adenosine triphosphate (ATP) synthase has been determined from the pathogenic anaerobic bacterium <i>Fusobacterium nucleatum</i>. The enzyme can hydrolyze ATP but is partially inhibited. The structure is similar to those of the F<sub>1</sub>-ATPases from <i>Caldalkalibacillus thermarum</i>, which is more strongly inhibited in ATP hydrolysis, and in <i>Mycobacterium smegmatis</i>, which has a very low ATP hydrolytic activity. The β<sub>E</sub>-subunits in all three enzymes are in the conventional ‘open’ state, and in the case of <i>C. thermarum</i> and <i>M. smegmatis</i>, they are occupied by an ADP and phosphate (or sulfate), but in <i>F. nucleatum</i>, the occupancy by ADP appears to be partial. It is likely that the hydrolytic activity of the <i>F. nucleatum</i> enzyme is regulated by the concentration of ADP, as in mitochondria.