|
Figure 4.
Figure 4. The Interaction between the D and B Proteins within
the Heterodimer(A) Stereo view of the D[3]B dimeric complex.
D[3], orange; B, blue. The β 5 strand of the D[3] protein pairs
with the β 4 strand of the B protein, forming a continuous
antiparallel β sheet. The loops L2, L3, L4, and L5 are
extending in the same direction.(B) Ball-and-stick model (stereo
view) of the main dimer interface stabilized by the paired β
strands and hydrophobic clustering of Phe-27 (strand β 2) of
the B protein and Phe-70 of the D[3] protein. The hydrogen bond
between the Gly-65 of D3 and Arg-73 of B stabilizes the
conformation of loop L5.(C) A close-up stereo view of the D[3]
and B protein interface including the hydrophobic cluster
between residues on the β sheet outer surface of the B protein
and residues on helix A and strands β 1β 2, and β 5 of the
D[3] protein. Pro-6 of the D[3] protein makes close contact with
Ala-33, the highly conserved Asp-35 and Asn-39, and Ile-41 of
the B protein.(D) The intersubunit salt bridge between Glu-21
(D[3]) and Arg-65 (B) and a cluster of arginines showing
stacking of the guanidinium groups (Arg-69 of D[3] and Arg-25
and Arg-49 of B). The sigma A–weighted 2Fo − Fc map
indicates the high quality of the electron density. Figure
produced with SETOR ([[3]12]).
|
