Fig. 1.13 Structure of the core subunits of Bos taurus mitochondrial Complex I. Single-particle cryo-EM
map at ~5-Å resolution. Top. Structural models of the 14 mammalian core subunits (ribbon representation)
and their electron density (transparent surface); the subunits are colored individually and labeled with text
in the same colors. The mitochondrial matrix is on top. Bottom. The seven membrane-bound mammalian
core subunits, viewed from the matrix. Arrows indicate the positions of the four TM helices in Thermus
thermophilus that are not present in B. taurus: three N-terminal TM helices in ND2 and one C-terminal TM
helix in ND1. The position of TM helix 4 in ND6 is different in B. taurus and T. thermophilus (marked
with stars). Note the very long amphipathic α-helix (in blue, ~110-Å long) that runs almost all the way
along the TM region, parallel to the membrane plane, at the level of the lipid polar head region (From
Vinothkumar et al. 2014. # 2014 Macmillan Publishers Limited, Nature. All rights reserved. See also
Efremov et al. 2010; Baradaran et al. 2013).
1.5 Membrane Protein/Lipid Interactions
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