Extended Data Fig. 6: Electrostatics of the peripheral arm.
From: Structure of the complex I-like molecule NDH of oxygenic photosynthesis
a–c, Left, surface model views of the peripheral arm with the NdhI β-hairpin, NdhO and NdhS coloured in cyan, purple and yellow, respectively. Right, corresponding electrostatic potential surfaces calculated at pH 8 (see Methods) with the colour key shown at the bottom. a, Peripheral arm viewed down the β-hairpin of NdhI. The electrostatic potential of this view shows two positive patches circled in white and labelled as NdhO-adjacent (O-site) and NdhS-adjacent (S-site). b, S-site viewed with the indicated rotational relationship to a with Arg69 of NdhS outlined in orange. c, O-site viewed with the indicated rotational relationship to b with the basic triplet (Lys89-Lys90-Lys91) of NdhI and Lys4-Lys5 of NdhO outlined in orange. d, Alignments of NdhO (top) and NdhS (bottom) homologues with β-strand regions indicated, numbered according to the T. elongatus sequence. Boxed regions indicate exposed regions facing the respective sites, and basic residues are coloured blue. Predicted chloroplast localization sequences are removed when applicable. The sequence of S. oleracea NdhS is not available. Residues 1–42 for T. elongatus NdhS are not conserved and are not observed in our structure, and have been removed for the purposes of alignment.
