For the latter it was observed that one simple point mutation (glycine to threonine) yielded a radically different product than that observed for the native protein.
Loss of the positive charge at amino-acid 482 by mutation to glycine or threonine yields a protein conferring much less resistance to the drug (Volk et al, 2002).
The WT structure of EGFR was also subject to the identical in silico mutational method in which the wild-type residue (Threonine) was mutated to itself (Threonine) to ensure that mutation process is uniform for all structures.
Mutation of His194 to threonine proved most significant, with a switch in specificity from NADH to NADPH [ kcat/Km NADH /kcat/Km NADPH) from 1.5 1 to 1 3.5, mostly as a result of a reduced Km for NADPH of approximately sevenfold in the His194Thr mutant.
Notably, the I539T mutation restored the wild-type NBD1 pattern in ΔF508: both protease resistant bands of ∼25 and 27 kDa that had been lost in ΔF508 NBD1 returned upon mutation of I539 to Threonine (Figure 4A, ◂).
Except for strain P12, all strains lack the EPIYA motif B due to a mutation of alanine to threonine resulting in EPIYT.
The mutation from leucine to threonine at position 504 results in the formation of an additional hydrogen bond between Gly501 and Leu504.
Although rs1062923 does induce a non-synonomous missense mutation from isoleucine to threonine, it is not known whether it is definitively functional.
Only AGC and AGT produced replacement mutations within the CDRs, of which the most prevalent was from serine to asparagine; other mutations included serine to threonine, tyrosine, aspartate, methionine and proline.
