Figure 15.

Accommodation of the G190W mutation by the NNRTI site. Ribbon diagram of the RT–EFV complex (PDB ID: 1FK9, [32]) containing a G190W mutation modeled using Pymol (DeLano Scientific, Palo Alto, CA, USA). The NNRTI site in the p66E structure is in principle able to accommodate the large Trp190 side chain in the same region that accommodates EFV. Introduction of the same mutation into the compact p51 structure results is substantial steric conflicts (not shown). The p66 palm domain is shown in blue, EFV is beige, and the mutated G190W residue is gray. Since the NNRTI site is present only in the extended (E) conformation, the G190W mutation increases the E/C ratio, promoting dimer formation as illustrated in Figure 14.