Fig. 1.

Mutational analysis of conserved residues on the IpaH9.8 NEL domain. (A) Surface representation of the IpaH1.4 NEL domain (PDB ID code 3CKD) (22), numbered using the IpaH9.8 sequence, color-coded by conservation according to the key. Residues mutated in this study are indicated in black with the catalytic cysteine indicated in red. Conserved interfaces are grouped into active site and distal site clusters. (B) Catalytic E3 Ub ligase activity of IpaH9.8 NEL domain mutants relative to the WT enzyme in vitro (n = 3).