Fig. 1

∆48 PGAM5 forms tubular filaments in solution composed of ring-like structures. a Domain architecture of constructs used in this study. Full-length PGAM5 is comprised of a single transmembrane helix containing a mitochondrial targeting sequence (MTS), a linker domain including the regulatory multimerization motif (MM), and a C-terminal PGAM phosphatase domain. The native cleavage site between residues 24 and 25, cleaved by PARL⁶, is marked with a green arrow. b Elution profiles for ∆48 and ∆90 PGAM5 constructs purified by size exclusion chromatography (SEC) using a Superose 6 column (GE Healthcare) in SEC buffer containing  20 mM Tris-Cl pH 8.0, 500 µM TCEP, and 150 mM NaCl. The corresponding oligomeric states of each peak observed in the chromatograms are indicated. c Representative EM micrographs of negatively stained protein samples taken from fractions corresponding to the two distinct peaks observed in the ∆48 PGAM5 purification. d SEC profiles for ∆48 PGAM5 in SEC buffer and NaCl at a final concentration of 150, 300, or 750 mM. EM micrographs of negatively stained samples of ∆48 PGAM5 taken directly from the primary peak obtained during purification are shown, highlighting the decomposition of filaments into rings at increasing salt concentrations. Scale bars in c and d correspond to 50 nm, except for the inset in c in which the scale bar corresponds to 10 nm