Fig. 2

Local conformational changes in the cN-II mutants revealed by X-ray crystallography. Wild-type protein subunits are colored in light/dark gray, mutant subunits are colored in yellow or orange, and relevant residues are represented as sticks. Mutated residues are highlighted with boldface font. a The R367Q mutation disrupts the local hydrogen bonding network. b The R238W substitution triggers changes at the oligomeric interface. The region spanning residues 385–410 adopts a helical arrangement in the wild type, while it is unstructured in the mutant. Missing loops were modeled using the ModLoop server (highlighted in blue and magenta for wild type and mutant, respectively). c The L375F mutation alters local intersubunit contacts due to steric hindrance of the more bulky phenylalanine residue