article published yes Jame A Letts author 322DA418-F248-11E8-B48F-1D18A9856A870000-0002-9864-3586 Leonid A Sazanov author 338D39FE-F248-11E8-B48F-1D18A9856A870000-0002-0977-7989 LeSa department The 1 MDa, 45-subunit proton-pumping NADH-ubiquinone oxidoreductase (complex I) is the largest complex of the mitochondrial electron transport chain. The molecular mechanism of complex I is central to the metabolism of cells, but has yet to be fully characterized. The last two years have seen steady progress towards this goal with the first atomic-resolution structure of the entire bacterial complex I, a 5 Å cryo-electron microscopy map of bovine mitochondrial complex I and a ∼3.8 Å resolution X-ray crystallographic study of mitochondrial complex I from yeast Yarrowia lipotytica. In this review we will discuss what we have learned from these studies and what remains to be elucidated. Elsevier2015 eng 00036536240001610.1016/j.sbi.2015.08.008 338135 - 145 J.A. Letts, L.A. Sazanov, Current Opinion in Structural Biology 33 (2015) 135–145. Letts JA, Sazanov LA. Gaining mass: The structure of respiratory complex I-from bacterial towards mitochondrial versions. <i>Current Opinion in Structural Biology</i>. 2015;33(8):135-145. doi:<a href="https://doi.org/10.1016/j.sbi.2015.08.008">10.1016/j.sbi.2015.08.008</a> J. A. Letts and L. A. Sazanov, “Gaining mass: The structure of respiratory complex I-from bacterial towards mitochondrial versions,” <i>Current Opinion in Structural Biology</i>, vol. 33, no. 8. Elsevier, pp. 135–145, 2015. Letts JA, Sazanov LA. 2015. Gaining mass: The structure of respiratory complex I-from bacterial towards mitochondrial versions. Current Opinion in Structural Biology. 33(8), 135–145. Letts, J. A., &#38; Sazanov, L. A. (2015). Gaining mass: The structure of respiratory complex I-from bacterial towards mitochondrial versions. <i>Current Opinion in Structural Biology</i>. Elsevier. <a href="https://doi.org/10.1016/j.sbi.2015.08.008">https://doi.org/10.1016/j.sbi.2015.08.008</a> Letts, James A., and Leonid A. Sazanov. “Gaining Mass: The Structure of Respiratory Complex I-from Bacterial towards Mitochondrial Versions.” <i>Current Opinion in Structural Biology</i>, vol. 33, no. 8, Elsevier, 2015, pp. 135–45, doi:<a href="https://doi.org/10.1016/j.sbi.2015.08.008">10.1016/j.sbi.2015.08.008</a>. Letts, James A, and Leonid A Sazanov. “Gaining Mass: The Structure of Respiratory Complex I-from Bacterial towards Mitochondrial Versions.” <i>Current Opinion in Structural Biology</i>. Elsevier, 2015. <a href="https://doi.org/10.1016/j.sbi.2015.08.008">https://doi.org/10.1016/j.sbi.2015.08.008</a>. 16832018-12-11T11:53:27Z2025-09-23T08:55:19Z