Fig. 3.

YaxA and YaxB interact via cis and trans interfaces within the YaxAB complex. a Cryo-EM map (left) and modeled structure (right) of the cis interface between YaxA (blue) and YaxB (pink) within a radial spoke (cis). Boxes labeled I and II indicate contact regions within the protomer pair that are displayed enlarged (right). Residues in interacting proximity are shown as sticks; hydrophobic side chains are colored in gold. Given the medium resolution of the cryo-EM map, the side chains were modeled as ideal rotamers in phenix.real_space_refine. b Depiction as in a, but of the trans interface between YaxA and YaxB from two adjacent radial spokes. Box III indicates the contact region within the protomer pair, colored as in a