Sandbox Reserved 1053: Difference between revisions

Czr A functions as a [https://en.wikipedia.org/wiki/Protein_dimer dimer]. The <scene name='69/694218/Monomeric_unit/1'>monomeric units</scene> form a dimer at the czr operon, repressing gene transcription. Each monomeric unit contains <scene name='69/694218/Helices/1'>five alpha helices</scene> seen in purple and <scene name='69/694218/B_sheets/1'>one anitparallel beta sheet</scene> displayed in yellow. Key [https://en.wikipedia.org/wiki/Alpha_helix helices] regulate the binding of DNA and Zn⁺². The <scene name='69/694220/2kjb_colored_alpha_4/1'>alpha 4 helices</scene> (green) are the location of DNA binding and the <scene name='69/694220/Zinc_pocket_with_residues/2'>alpha 5 helices</scene> (red) contain the Zn⁺² binding site. As Zn⁺² ions bind to the alpha 5 helices, the alpha 5 helices move and push the alpha 4 helices into a conformation with low affinity for DNA (Figure 2). Two seperate PDB codes exist for Czr A: Czr A with DNA bound (2KJB) and Czr A with zinc⁺² bound (2KJC). Unfortunately, zinc ions are not visible in the 2KJC NMR structure that was obtained for Czr A.