Figure 2

LIR-2 D1D2 Crystal structure. A: Ribbon diagram of the structure LIR-2 D1D2 and comparison with the LIR-1 D1D2 structure. Dashed lines indicate disordered loops. Arrows indicate the single turn of 3₁₀ helix observed in LIR-2 D1 (residues 52–55), in comparison to the longer 3₁₀ helical segment (residues 44–57) in the same region of LIR-1 D1. 4₁₀ and 3₁₀ helices are shown in red, Polyproline II helices in green. The root mean square deviation between the two structures is 3.05 Å for domain 1 and 2.31 Å for D2 for all carbon alpha atoms. B: Conformational change in D2 146–154 loop relative to LIR-1. The LIR-2 loop is shown in ball-and-stick representation. The LIR-1 loop is shown in blue as a ribbon diagram. The conformational difference is maximal at residue Ala 150 (equivalent to Ala 151 in LIR-1), where the Cα positions differ by 14 Å. C: Crystal contacts involving the D2 146–154 loop for LIR-2 and LIR-1 (147–155). Both LIR-1 (left panel) and LIR-2 (right panel) are shown in cyan with the loop region highlighted in red, and the equivalent neighboring molecule shown in grey.