Crystal structure of LeuD from Methanococcus jannaschii

► We report the structure of LeuD from Methanococcus jannaschii. ► The C-terminal helix of MjLeuD is important in homodimer formation. ► V28 residue is responsible for recognizing the isopropyl group of 3-IPM. ► Two LeuD subfamilies show differences in structure and substrate recognition region.