Sandbox Reserved 485: Difference between revisions
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=Ran-GDP (Ras related nuclear protein)= | =Ran-GDP (Ras related nuclear protein)= | ||
<Structure load='3gj0' size=' | <Structure load='3gj0' size='275' frame='true' align='right' caption='(PDB:3GJ0) Crystal Structure of Human RanGDP Asymmetric Unit' scene='Insert optional scene name here' /> | ||
==Introduction== | ==Introduction== | ||
Ras related nuclear protein, known as the Ran protein, is the most abundant small GTPase in the cell and serves a variety of key roles in cellular regulation and protein transport. Ran is a binding protein that is a subset of the RAS superfamily that actively binds between GDP and GTP to regulate the import and export of RNA molecules and cytoplasmic material. The Ran protein also plays a key role during interphase and mitosis as the cell progresses through the cell cycle and DNA is synthesized. The majority of the Ran protein is located within the nucleus of eukaryotic cells and interacts with a a variety of proteins due to its diverse uses.<ref>http://www.sciencedirect.com.prox.lib.ncsu.edu/science/article/pii/S0378111911002666</ref> | Ras related nuclear protein, known as the Ran protein, is the most abundant small GTPase in the cell and serves a variety of key roles in cellular regulation and protein transport. Ran is a binding protein that is a subset of the RAS superfamily that actively binds between GDP and GTP to regulate the import and export of RNA molecules and cytoplasmic material. The Ran protein also plays a key role during interphase and mitosis as the cell progresses through the cell cycle and DNA is synthesized. The majority of the Ran protein is located within the nucleus of eukaryotic cells and interacts with a a variety of proteins due to its diverse uses.<ref>http://www.sciencedirect.com.prox.lib.ncsu.edu/science/article/pii/S0378111911002666</ref> | ||
==Structure== | ==Structure== | ||
[[Image:3gj0Ramachandran.jpg|thumb|left| | [[Image:3gj0Ramachandran.jpg|thumb|left|130px|cap=text| Human RanGDP Ramachandran Plot from X-ray Crystallography at 2.3Å]] | ||
The Ran protein is a small binding protein that consists of 221 residues. The <scene name='Sandbox_Reserved_485/Rangdp_secondary_structure/1'>secondary structure</scene> consists of a mixture of eleven, 70-residue alpha-helices and twelve, 55-residue beta-sheets. The Ran protein is made up of two asymmetric units, Chain A and Chain B. Each unit binds to a Mg2+ and a GDP. X-ray crystallography, examined at 2.3A, produced a Ramachandran plot that determined the crystal structure of Ran bound GDP and Mg2+. The crystal structure showed that the Ran protein shares a high resemblance to the G-domain of the Ras protein. However significant discrepancies were observed in the GDP and Mg2+ binding sites, suggesting that the binding of GTP results in significant conformational changes to the protein.<ref>http://www.rcsb.org/pdb/explore/explore.do?structureId=3gj0</ref> Ran proteins contain a cis-glutamine which is responsible for positioning nucleophilic water, which in turn activaes GTPase activity. Along with the consistencies observed in the G-domain, an extended chain and an a-helix were observed on the carboxy terminus while a compliant amino-terminal stretch and an acidic tail were observed on the amino-terminal end. <ref>http://www.nature.com/emboj/journal/v27/n7/full/emboj200830a.html</ref> | The Ran protein is a small binding protein that consists of 221 residues. The <scene name='Sandbox_Reserved_485/Rangdp_secondary_structure/1'>secondary structure</scene> consists of a mixture of eleven, 70-residue alpha-helices and twelve, 55-residue beta-sheets. The Ran protein is made up of two asymmetric units, Chain A and Chain B. Each unit binds to a Mg2+ and a GDP. X-ray crystallography, examined at 2.3A, produced a Ramachandran plot that determined the crystal structure of Ran bound GDP and Mg2+. The crystal structure showed that the Ran protein shares a high resemblance to the G-domain of the Ras protein. However significant discrepancies were observed in the GDP and Mg2+ binding sites, suggesting that the binding of GTP results in significant conformational changes to the protein.<ref>http://www.rcsb.org/pdb/explore/explore.do?structureId=3gj0</ref> Ran proteins contain a cis-glutamine which is responsible for positioning nucleophilic water, which in turn activaes GTPase activity. Along with the consistencies observed in the G-domain, an extended chain and an a-helix were observed on the carboxy terminus while a compliant amino-terminal stretch and an acidic tail were observed on the amino-terminal end. <ref>http://www.nature.com/emboj/journal/v27/n7/full/emboj200830a.html</ref> | ||
