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Figure 4.
Fig. 4. Dimerization of GRIP PDZ6. A, dimeric structure
of PDZ6 domain. PDZ6 domains form a dimer via interaction of
antiparallel A strands
and A- D loops.
Peptide ligands bound to the opposite side of the PDZ6 dimer are
represented in ball-and-stick. B, self-association of two GRIP
PDZ6 domains related by a 2-fold crystallographic axis was
observed in the peptide-free PDZ6 crystal. Each C terminus
serves as a ligand for a neighboring PDZ molecule. C, effects of
mutations on dimerization. Molecular weights of mutants Y671D
and R731D and a wild type PDZ domain were estimated by size
exclusion chromatography (Superdex 75 HR 16/60 column). The
mutated residues, Y671D and R718D, were shown in ball and stick
with van der Waals radius in A and B. The elution profiles of a
wild type, Y671D and R718D mutants. This result suggests that
the dimer in solution is the form shown in A. D, the variable
residues within the PDZ6 domains of GRIP homologues are
represented in ball-and-stick. Only one variable residue,
Ile-669, which is Val in GRIP2, is located in the dimeric
interface.
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