Table 1.

His mutants designed to distinguish between tight and loose tetrameric packing arrangement

Mutated residues are listed in the first column from the left, followed by nomenclature introduced for each mutant. Cartoon models in the third and fourth columns show mutated residues in the tight and loose crystal arrangements, respectively, for the respective mutant (mutant side chains were oriented by eye, without energy minimization). Approximate distances between nitrogen atoms are denoted by dotted lines and expressed in Ångstroms. Individual subunits are color coded as in Fig. 1: A, green; B, red; C, blue; D, yellow. The fifth column contains a top view of the LBDs in the arrangement that predicts cross-linking of the respective mutant (T-tight or L-loose). Black lines and orange triangles indicate expected zinc coordination sites. The HH control mutant, for which no cross-link was predicted, is included for comparison. To see this table in color, go online.