Figure 1 - full size



	Figure 1 - full size

Figure 1.
FIGURE 1. Structure of human centrin-2 bound to a human XPC-derived peptide. A, sequence of the HsCen-2 recognition site from HsXPC structurally aligned with sequences of skeletal and smooth muscle myosin light chain kinase (skMLCK and smMLCK) and Kar1p from structures with calmodulin and yeast centrin (or caltractin). The XPC peptide structure consists of residues Asn^847-Arg^863, the HsXPC sequence underlined. Essential HsXPC residues interacting to form -helical coiled-coil are indicated in red. Shaded pink are important HsXPC residues interacting with HsCen-2. Positions numbered "1-5-8-14" of key interfacial residues in skeletal muscle myosin light chain kinase and smooth muscle myosin light chain kinase bound to calmodulin are shown for comparison in purple. B, rainbow ribbon trace of the main chains of HsCen-2 with HsXPC and two bound Ca^2+ metals at the C-terminal domain. An ordered helical linker separates N-terminal (blue)(Nterm) and C-terminal (red)(Cterm) domains. The entire XPC peptide is -helix. C, two complexes are found in the asymmetric unit. They interact solely through bound XPC peptides that form an -helical coiled-coil structure. D, the two independent complex structures are nearly equivalent in overall conformation.