12as: Difference between revisions
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==Overview== | ==Overview== | ||
The crystal structure of E. coli asparagine synthetase has been determined, by X-ray diffraction analysis at 2.5 A resolution. The overall structure, of the enzyme is remarkably similar to that of the catalytic domain of, yeast aspartyl-tRNA synthetase despite low sequence similarity. These, enzymes have a common reaction mechanism that implies the formation of an, aminoacyl-adenylate intermediate. The active site architecture and most of, the catalytic residues are also conserved in both enzymes. These proteins, have probably evolved from a common ancestor even though their sequence, similarities are small. The functional and structural similarities of both, enzymes suggest that new enzymatic activities would generally follow the, recruitment of a protein catalyzing a similar chemical . | The crystal structure of E. coli asparagine synthetase has been determined, by X-ray diffraction analysis at 2.5 A resolution. The overall structure, of the enzyme is remarkably similar to that of the catalytic domain of, yeast aspartyl-tRNA synthetase despite low sequence similarity. These, enzymes have a common reaction mechanism that implies the formation of an, aminoacyl-adenylate intermediate. The active site architecture and most of, the catalytic residues are also conserved in both enzymes. These proteins, have probably evolved from a common ancestor even though their sequence, similarities are small. The functional and structural similarities of both, enzymes suggest that new enzymatic activities would generally follow the, recruitment of a protein catalyzing a similar chemical reaction. | ||
==About this Structure== | ==About this Structure== | ||
12AS is a | 12AS is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with ASN and AMP as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Aspartate--ammonia_ligase Aspartate--ammonia ligase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=6.3.1.1 6.3.1.1] Structure known Active Sites: NU1 and NU2. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=12AS OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: nitrogen fixation]] | [[Category: nitrogen fixation]] | ||
''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on | ''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Mon Nov 5 12:28:40 2007'' | ||
