3-1 TRP Repressor

 

APO TRP REPRESSOR

ID number:
    1WRT
Authors:
     D.ZHAO,Z.ZHENG
Resolution:
     NOT APPLICABLE.
Residue number in one monomer:
     105
Cofactor number in whole complex:
     0

 

HOLO TRP REPRESSOR

ID number:
    1WRS
Authors:
    D.ZHAO,Z.ZHENG
Resolutions:
    NOT APPLICABLE.
Residue number in one monomer:
    105
Cofactor number in whole molecule:
    2

The Role of Trp in the Trp Repressor Complex

The binding of Tryptophan to the repressor induces a conformational
change and alter the orientation of the recognition helices(5).
The binding trptophan are wedged between the helix 3 and helix 5
(the recognition helix)of each monomer of the complex. Tryptophan
starvation causes the recognition helices fold in toward the core,
this makes the distance between the two DNA
binding sites of the repressor too short by 5-6 angstroms to allow them
. to fit into the majot groove. But when the tryptophan is plentiful, the
. recognition helices are properly poised 34 agnstroms apart for binding
DNA in the major groove.

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