|
Figure 3.
FIG. 3. Comparison of the LBPs of ERR  and ER  . A,
superimposition of selected parts of the ERR LBD·DES complex
(green) with the ER LBD·DES complex
(red) (PDB code 3ERD [PDB]
). Although the overall ligand binding mode is very similar in
both complexes, the DES binding position is shifted by about 0.5
Å in the cavity of ERR relative to ER . In
contrast to ERR , H12 of the ER LBD can
occupy the agonist position since there is no steric clash with
Leu-525 (corresponding to Phe-435 in ERR ). B, superimposition
of selected parts of the ERR LBD·4-OHT
complex (orange) with the ER LBD·4-OHT
complex (blue) (PDB code 3ERT [PDB]
). In ERR , the 4-OHT binding
position is slightly rotated and mainly differs around the B
ring and the amine moiety. The altered 4-OHT binding results
from steric constraints imposed by Leu-345 (Ile-424 in ER ), a
slightly shifted relative position of H7, and the side chain of
Phe-435 (Leu-525 in ER ). C, left,
superimposition of 4-OHT (blue), E2 (light gray), and RAL
(black) as observed in the LBP of the respective ER complexes (PDB codes:
ER /E2, 1ERE [PDB]
; ER /RAL, 1ERR [PDB]
). Right, superimposition of 4-OHT as observed in the cavity of
ERR (orange) with E2 (light
gray) and RAL (brown) bound to ER . E2 and RAL protrude
deeper into the cavity of ER than 4-OHT and do not
bind to ERR due to insufficient
space in the LBP.
|
