Fig. 4: Carotenoids in the Rba. sphaeroides LH1.
From: A previously unrecognized membrane protein in the Rhodobacter sphaeroides LH1-RC photocomplex
a Typical structures and density maps (3σ) of two spheroidenes (yellow and orange) relative to the position of a BChl a (red) in the LH1 complex with different configurations. b Two groups of the spheroidenes (yellow and orange sticks for Group-A and Group-B, respectively) in the Rba. sphaeroides LH1 in comparison with the carotenoids in the Tch. tepidum LH1 (black sticks, PDB:5Y5S). The structures were superimposed by Cα carbons of the LH1 αβ-polypeptides between Rba. sphaeroides (transparent green and slate-blue cylinders) and Tch. tepidum (transparent gray cylinders). c Close contacts (<4.0 Å, dashed lines) between a Group-B spheroidene and its surrounding αβ-polypeptides. d Side view of the surface representation shows a sealed fence for the Rba. sphaeroides LH1 complex. Color scheme: LH1-α, green; LH1-β, slate-blue; BChl a, red; spheroidenes, yellow (Group-A) and orange (Group-B).
