Figure 3. Protein sequence alignments via
Protein Basic Local Alignment Search Tool (BLASTP) of the regions of
the human proteins of the BEST family (BEST1–4) and of the BEST1
proteins containing the p.T4A, p.G15D, and p.I230T novel mutations. The
residues at position 4, 15, and 230 are highly conserved from mammals
to flies as well as in two-thirds of the human BEST proteins.
Interestingly, when nonconserved, the amino acids are replaced by
residues of the same classes (neutral polar threonine at position 4 is
changed to neutral polar asparagine and serine in human BEST4 and worm
BEST1 proteins, respectively; nonpolar uncharged glycine at position 15
is changed to uncharged nonpolar phenylalanine in the human BEST3 and
worm BEST1 sequences, respectively; neutral nonpolar isoleucine at
position 230 is changed to valine in the human BEST3 and worm BEST1
proteins). Interestingly, the three novel BEST1 mutations reported here
are expected to change the polarity and/or the charge of the protein.
The p.T4A mutation changes a polar to a nonpolar amino acid, while the
p.G15D and I230T mutations change nonpolar uncharged residues to polar
acidic (aspartic acid) and neutral nonpolar (threonine) residues,
respectively.