Data collection and structure determination

X-ray diffraction datasets were collected at the SPring-8 beamlines of BL32XU and BL41XU with the automated data collection system ZOO (51) and processed with KAMO (52) for automatic data processing using XDS (53). For the SeMet-substituted TM domain of TpCorC, selenium sites were identified from the SAD data with SHELXD (54, 55). The initial phase was calculated and improved with SHELXE (54, 55), followed by automatic model building. The model was then further manually rebuilt with Coot (56) and refined with PHENIX (57). The structures of the wild type and the V101A mutant of the TpCorC TM domain were determined by molecular replacement with Phaser using the initial model of the SeMet-substituted TM domain of TpCorC (58) and further refined through multiple rounds of manual model building by Coot (56) and refinement by PHENIX (57).

The structure of the TpCorC CBS domain constructs of TpCorC (residues 183 to 361, Y255A, and residues 202 to 361) were initially determined by molecular replacement with Phaser using the homology model from SWISS-MODEL (59). The structure was further manually rebuilt using Coot (56) and refined by PHENIX (57).

The Ramachandran plots were calculated with MolProbity (60). Data collection and refinement statistics are summarized in table S2. All figures showing structures were generated using PyMOL (https://pymol.org/).