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September 2002; 62 (3)
[Index by Author]
[Cover Caption]
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About the cover: DAT TM3 electrostatic potential models. A,
dot surface displays of electrostatic potentials in WT (left) and F154A
(right) TM3 helices. Each TM3 was built as an
-helix and
energy-minimized. The 21 amino acids of TM3 cross the plasma membrane
from the lower (N-terminal, cytoplasmic) side to the upper (C-terminal,
extracellular) side. F154A is indicated by arrows. Dot surfaces were
displayed using Sybyl 6.6 "vdW Dot Surface" with red indicating
electrostatic potential measures of "V" > 24.9; orange, yellow or
green 3.3 > V > 0, cyan 0 > V >
3.3 and blue, purple or white V <
24.9. "V" is defined as described previously [Weiner PA,
Langridge R, Blaney JM, Scharfer R, and Kollman PK (1982) Electrostatic
potential molecular surfaces. Proc Natl Acad Sci USA
79:3754-3758] at an arbitrary distance of 1.4 Å. At the
helical side important for cocaine binding, there are seven residues;
three (42%) are decreased and another three increased in electrostatic
potentials. At the side for dopamine uptake, there are eight residues;
seven of them (87%) are decreased and none of them is increased in
electrostatic potentials. Indicated are amino acid residues visible on
this graph to the reader and whose electrostatic potentials are reduced
by the F154A substitution. Italic lables denote residues hiding from
the reader (located at the opposite side of the domain). #, increased
electrostatic potentials for asparagine 157 (above the arrow) and
phenylalanine 150 (below the arrow). Scale bar, 5 Å. Mol
Pharmacol 61:885-981.