Sandbox108: Difference between revisions
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==Glutamine synthetase assignment by UMBC undergraduate students | ==Glutamine synthetase assignment by UMBC undergraduate students== | ||
{{STRUCTURE_2gls | PDB=2gls | SCENE= }} | {{STRUCTURE_2gls | PDB=2gls | SCENE= }} | ||
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Tertiary structure of protein is characterized by the “global” folding of a polypeptide chain [http://www.stanford.edu/group/pandegroup/folding/education/prstruc.html] and mostly affected by <scene name='Sandbox108/Hydrophobic/1'>Hydrophobic(purple)</scene>(<scene name='Sandbox108/Polar/1'>polar(blue)</scene>) interaction and hydrogen bonding. In general, hydrophobic interaction is a major driving force determining the most tertiary structure of the proteins. Hydrogen bonding is crucial in stabilizing the tertiary structure as well.[http://webhost.bridgew.edu/fgorga/proteins/proteins.htm] Also, disulfide bonds stabilize the tertiary structure in residues such as cysteine residues.[http://webhost.bridgew.edu/fgorga/proteins/proteins.htm] However, for Salmonella typhimurium it is mostly influenced by the helix-helix interactions between 12-subunits enzymes within two layers.[http://www.stanford.edu/group/pandegroup/folding/education/prstruc.html] | |||
Glutamine synthetase from Salmonella typhimurium is the 12-subunits enzyme and has 23 helix-helix interactions involving helices of chain A with four different types of interactions. [http://www.ebi.ac.uk/thornton-srv/databases/cgi-bin/pdbsum/GetPage.pl?pdbcode=2gls&template=protein.html&o=HELIX_INTERACTIONS&l=1&s=1&c=7&chain=A] The 12-subunits enzyme are arranged in two layers of six, such as <scene name='Sandbox108/Glu_131/1'>Glu-131</scene> | |||
Glutamine synthetase from Salmonella typhimurium is the 12-subunits enzyme, and has 23 helix-helix interactions involving helices of chain A with four different types of interactions. [http://www.ebi.ac.uk/thornton-srv/databases/cgi-bin/pdbsum/GetPage.pl?pdbcode=2gls&template=protein.html&o=HELIX_INTERACTIONS&l=1&s=1&c=7&chain=A] The 12-subunits enzyme are arranged in two layers of six, such as <scene name='Sandbox108/Glu_131/1'>Glu-131</scene> which is the one of the protein residues of Salmonella typhimurium; at the interface of pairs of subunits within each layer, six anti-parallel beta strands formed cylindrical active sites.[http://www.ncbi.nlm.nih.gov/pubmed/2572586?dopt=Abstract] Each active site holds two <scene name='Sandbox108/Mn/3'>Mn2+</scene> ions surrounded by some <scene name='Sandbox108/Histidyl_side_chain/1'>histidyl side chains.</scene> [http://www.ncbi.nlm.nih.gov/pubmed/2572586?dopt=Abstract] Also, the protein ligands to Mn2+ 469 are <scene name='Sandbox108/Glu_131/3'>Glu-131</scene>, <scene name='Sandbox108/Glu_212/3'>Glu-212</scene>, and <scene name='Sandbox108/Glu_220/2'>Glu-220</scene>; those to Mn2+ 470 are <scene name='Sandbox108/Glu_129/2'>Glu-129</scene>, <scene name='Sandbox108/His_269/1'>His-269</scene>, and <scene name='Sandbox108/Glu_357/2'>Glu-357</scene>.[http://www.ncbi.nlm.nih.gov/pubmed/2572586?dopt=Abstract] Glutamine from Salmonella typhimurium has 12-subunits of each of them in pairs within two layers. COOH terminus and a helical thong, which inserts into a <scene name='Sandbox108/Hydrophobic/1'>Hydrophobic(purple)</scene> pocket formed by two neighboring subunits on the opposite ring, hold the two layers of subunits tightly.[http://www.ncbi.nlm.nih.gov/pubmed/2572586?dopt=Abstract] Also, <scene name='Sandbox108/Hydrogen_bonded_beta-sheet/1'>hydrogen-bonded beta sheet interactions(black)</scene> can affect the form of tertiary structure, but <scene name='Sandbox108/Hydrophobic/1'>Hydrophobic(purple)</scene> interactions will contribute to the stability of the intersubunit between two layers more efficiently.[http://www.ncbi.nlm.nih.gov/pubmed/2572586?dopt=Abstract] In the other hand, the most effective interaction in glutamine synthetase from Salmonella typhimurium is the helix-helix interactions. The folding of the proteins can be affected by the 12-subunits in the residues. In the case of Salmonella typhimurium the helices of chain A has <scene name='Sandbox108/Charged_region/1'>the charged regions(blue and red)</scene>, while most glutamine has uncharged side chain which formed by replacing the hydroxyl of glutamic acid with an amine functional group. | |||
As a result, the only helix-helix interactions will be the most powerful sources of being in the glutamine synthetase of Salmonella typhimurium. | |||
