Fig. 2.

Crystal structure of apo-LmCld. (A) Overlay of pentameric apo-LmCld (green) and pentameric holo-NdCld (pdb-code: 3NN1) (yellow). (B) Overlay of the heme-binding sites of apo-LmCld (green) and holo-NdCld (yellow); residue-labels of holo-NdCld are underlined. Ribbon representation of apo-LmCld (C) and holo-NdCld (E); for better orientation the heme group of holo-NdCld was placed to the heme binding site of apo-LmCld (gray). Representation of the surfaces of apo-LmCld (D) and holo-NdCld (F). Substrate-channel forming secondary structural elements of holo-NdCld and respective residues of apo-LmCld are depicted in red (C–F). Figures were generated using PyMOL (http://www.pymol.org/). (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.)