1o7l: Difference between revisions

ModE is a bacterial transcriptional regulator that orchestrates many, aspects of molybdenum metabolism by binding to specific DNA sequences in a, molybdate-dependent fashion. We present the crystal structure of, Escherichia coli ModE in complex with molybdate, which was determined at, 2.75A from a merohedrally twinned crystal (twin fraction approximately, 0.30) with space group P4(3). We now have structures of ModE in both its, "switched on" (ligand-bound) and "switched off" (apo) states. Comparison, with the apo structure shows that ligand binding leads to extensive, conformational changes not only in the molybdate-binding domain, but also, in the DNA-binding domain. The most obvious difference is the loss of the, pronounced asymmetry between the two chains of the ModE dimer, which had, been a characteristic property of the apo structure. Another major change, concerns the relative orientation of the two DNA-interacting winged, helix-turn-helix motifs. Manual docking of an idealized DNA structure, suggests that this conformational change should improve DNA binding of the, activated molybdate-bound ModE.

1O7L is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with CL, CA and MOO as [http://en.wikipedia.org/wiki/ligands ligands]. Structure known Active Site: MO1. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1O7L OCA].  

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