1k7y: Difference between revisions
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New page: left|200px<br /><applet load="1k7y" size="450" color="white" frame="true" align="right" spinBox="true" caption="1k7y, resolution 3.0Å" /> '''E. coli MetH C-termin... |
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[[Image:1k7y.jpg|left|200px]]<br /><applet load="1k7y" size=" | [[Image:1k7y.jpg|left|200px]]<br /><applet load="1k7y" size="350" color="white" frame="true" align="right" spinBox="true" | ||
caption="1k7y, resolution 3.0Å" /> | caption="1k7y, resolution 3.0Å" /> | ||
'''E. coli MetH C-terminal fragment (649-1227)'''<br /> | '''E. coli MetH C-terminal fragment (649-1227)'''<br /> | ||
==Overview== | ==Overview== | ||
B(12)-dependent methionine synthase (MetH) from Escherichia coli is a | B(12)-dependent methionine synthase (MetH) from Escherichia coli is a large modular protein that uses bound cobalamin as an intermediate methyl carrier. Major domain rearrangements have been postulated to explain how cobalamin reacts with three different substrates: homocysteine, methyltetrahydrofolate and S-adenosylmethionine (AdoMet). Here we describe the 3.0 A structure of a 65 kDa C-terminal fragment of MetH that spans the cobalamin- and AdoMet-binding domains, arranged in a conformation suitable for the methyl transfer from AdoMet to cobalamin that occurs during activation. In the conversion to the activation conformation, a helical domain that capped the cofactor moves 26 A and rotates by 63 degrees, allowing formation of a new interface between cobalamin and the AdoMet-binding (activation) domain. Interactions with the MetH activation domain drive the cobalamin away from its binding domain in a way that requires dissociation of the axial cobalt ligand and, thereby, provide a mechanism for control of the distribution of enzyme conformations. | ||
==About this Structure== | ==About this Structure== | ||
1K7Y 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 SO4 and B12 as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Methionine_synthase Methionine synthase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.1.1.13 2.1.1.13] Full crystallographic information is available from [http:// | 1K7Y 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 <scene name='pdbligand=SO4:'>SO4</scene> and <scene name='pdbligand=B12:'>B12</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Methionine_synthase Methionine synthase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.1.1.13 2.1.1.13] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1K7Y OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Bandarian, V.]] | [[Category: Bandarian, V.]] | ||
[[Category: Huddler, D | [[Category: Huddler, D P.]] | ||
[[Category: Lennon, B | [[Category: Lennon, B W.]] | ||
[[Category: Ludwig, M | [[Category: Ludwig, M L.]] | ||
[[Category: Matthews, R | [[Category: Matthews, R G.]] | ||
[[Category: Pattridge, K | [[Category: Pattridge, K A.]] | ||
[[Category: B12]] | [[Category: B12]] | ||
[[Category: SO4]] | [[Category: SO4]] | ||
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[[Category: motion of 4-helix bundle]] | [[Category: motion of 4-helix bundle]] | ||
''Page seeded by [http:// | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:31:06 2008'' | ||
