Fig. 2: DAG binding mode of yCPT1.

a Model of yCPT1 protomer as viewed from the membrane plane. The box highlights the position of the DAG-binding site and is shown expanded in panels b and c. The cryo-EM density of DAG is shown in blue with the model also shown in blue. Acyl-chains from DAG occupy the hydrophobic spaces inside of yCPT1. b Enlarged view of DAG-binding site. Each of the two acyl-chains of DAG occupies two distinct hydrophobic channels: Channel 1, the channel between TM4 and TM6; Channel 2, the channel between TM5 and TM6. c The same DAG-binding site is viewed from the lumenal side. Note that Phe146 shown as sticks is located at the exit site of channel 1. d DAG-surrounding residues in yCPT1. LigPlot2⁵¹ is used for the analysis and the illustration. Phe146 is shown in coral. e, f Acyl-chain preference of yCPT1 WT (blue circles) and yCPT1 F146L (coral triangles). Choline phosphotransferase activity was determined by quantifying the level of CMP released from CDP-choline (1 mM) using DAG 16:0-16:0 or DAG 18:1-18:1 at the indicated concentration. g The preference for C18-DAG was determined by dividing the amount of CMP released with PC 18:1-18:1 (300 μM) by that of CMP with PC 16:0-16:0 (300 μM). Data are presented as the mean ± SD from three independent measurements. Statistical significance was determined by unpaired two-sided t-test. Source data are provided as a Source Data file.