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Proteopedia Page Contributors and Editors (what is this?)Proteopedia Page Contributors and Editors (what is this?)

OCA, Ben Zercher, Geoffrey C. Hoops, Katelyn Baumer, Mary Liggett, Jakob Jozwiakowski

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 == Biological Function ==
-Czr A is a transcriptional repressor protein responsible for the regulation of the Chromosome Determined Zinc Responsible (Czr) operon. The Czr operon contains genes for the proteins Czr A and Czr B. Czr B is a Zinc transport protein which moves Zinc out of a cell. Czr A regulates this process by controlling the degree to which Czr B is expressed. When relatively low amounts of zinc are present in the cell Czr A will bind to DNA, inhibiting expression of Czr B, enabling the cell to retain Zinc. When high amounts of Zinc 2+ are present in the cell, each Czr A molecule binds two Zn 2+ ions, and forcing a conformational change. The zinc binding conformation of Czr A is not capable of binding to DNA, as the new conformation disrupts the DNA binding pocket. Conversely, the DNA binding conformation of Czr A does not allow for the binding of either Zn 2+ atom.
+Czr A is a transcriptional repressor protein responsible for the regulation of the Chromosome Determined Zinc Responsible (Czr) operon. The Czr operon contains genes for the proteins Czr A and Czr B. Czr B is a Zinc transport protein which moves Zn 2+ out of a cell. Czr A regulates this process by controlling the degree to which Czr B is expressed. When relatively low amounts of zinc are present in the cell Czr A will bind to DNA,preventing the progression of RNA polymerase and thus inhibiting expression of Czr B. Decreased expression of Czr B results in the ability of the cell to retain Zn 2+ more readily. Because Czr A and Czr B are transcribed as part of the same operon, there must be a way that Czr A is inhibited to allow full transcription of Czr B. Czr A is inhibited by the binding of two Zn 2+ ions, which is ideal considering that this mechanism allows for Zn 2+ concentration inside the cell to determine the need for Zn 2+ transport out of the cell. Zn 2+ competitively inhibits the binding of DNA to Czr A. Czr A has two distinct conformations, one of which binds Zn 2+ with very high affinity that has virtually no affinity towards DNA binding, the other having a high affinity for DNA binding but very little affinity for Zn 2+.
-== Structural Overview ==
 ===DNA Binding ===
 ===Zinc Binding ===