Sandbox Reserved 1069: Difference between revisions
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==Structure== | ==Structure== | ||
YiiP is a homodimer [https://en.wikipedia.org/wiki/Protein_dimer (protein dimer)], with each monomer consisting of 238 residues with a TransMembrane (<scene name='69/694236/Tmd/1'>TMD</scene>) and C-Terminal (<scene name='69/694236/Ctd/1'>CTD</scene>) domain that are connected via a charge interlocking mechanism located on a flexible loop. | YiiP is a homodimer [https://en.wikipedia.org/wiki/Protein_dimer (protein dimer)], with each monomer consisting of 238 residues with a TransMembrane (<scene name='69/694236/Tmd/1'>TMD</scene>) and C-Terminal (<scene name='69/694236/Ctd/1'>CTD</scene>) domain that are connected via a charge interlocking mechanism located on a flexible loop. In total, the Yiip protein has three Zn<sup>2+</sup> binding sites, site A, B, and C. Site A is located in both TMDs of the protein, site C is located in the CTD, and site B is located at the junction of the two domains. The TMD, where Zn<sup>2+</sup> binding site A resides, consists of 6 transmembrane (TM) <scene name='75/756372/Sixhelices/1'>helices</scene>, 4 of which (TM1, TM2, TM4, TM5) pivot about the ion binding site A. The remaining two helices, TM3 and TM6, are oriented <scene name='75/756372/2antiparallel/1'>antiparallel</scene> to the bundle. Movement of these helices play a role in the function of Zn<sup>2+</sup> transport. | ||
A large portion of the protein containing binding site C, the CTD, approximately 30 Å in length<sup>[https://www.bnl.gov/isd/documents/71335.pdf]</sup>, protrudes into the cytoplasm functioning as a Zn<sup>2+</sup> sensor within the cell. Zn<sup>2+</sup> binding at site C helps hold the CTD together and is thought to stabilize conformational changes in YiiP. YiiP has two different functional conformations which dictates whether or not YiiP is open to the periplasm or the cytoplasm. An interlocked salt bridge connects the two domains with the Lys77 and the Asp207 from each monomer. This [https://en.wikipedia.org/wiki/Salt_bridge_(protein_and_supramolecular) salt bridge] acts as the hinge for Yiip's conformational changes. | A large portion of the protein containing binding site C, the CTD, approximately 30 Å in length<sup>[https://www.bnl.gov/isd/documents/71335.pdf]</sup>, protrudes into the cytoplasm functioning as a Zn<sup>2+</sup> sensor within the cell. Zn<sup>2+</sup> binding at site C helps hold the CTD together and is thought to stabilize conformational changes in YiiP. YiiP has two different functional conformations which dictates whether or not YiiP is open to the periplasm or the cytoplasm. An interlocked salt bridge connects the two domains with the Lys77 and the Asp207 from each monomer. This [https://en.wikipedia.org/wiki/Salt_bridge_(protein_and_supramolecular) salt bridge] acts as the hinge for Yiip's conformational changes. | ||