1k98
From Proteopedia
(New page: 200px<br /><applet load="1k98" size="450" color="white" frame="true" align="right" spinBox="true" caption="1k98, resolution 3.75Å" /> '''AdoMet complex of Me...) |
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| - | [[Image:1k98.jpg|left|200px]]<br /><applet load="1k98" size=" | + | [[Image:1k98.jpg|left|200px]]<br /><applet load="1k98" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1k98, resolution 3.75Å" /> | caption="1k98, resolution 3.75Å" /> | ||
'''AdoMet complex of MetH C-terminal fragment'''<br /> | '''AdoMet complex of MetH C-terminal fragment'''<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== | ||
| - | 1K98 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:// | + | 1K98 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=1K98 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 13:31:34 2008'' |
Revision as of 11:31, 21 February 2008
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AdoMet complex of MetH C-terminal fragment
Overview
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
1K98 is a Single protein structure of sequence from Escherichia coli with and as ligands. Active as Methionine synthase, with EC number 2.1.1.13 Full crystallographic information is available from OCA.
Reference
Domain alternation switches B(12)-dependent methionine synthase to the activation conformation., Bandarian V, Pattridge KA, Lennon BW, Huddler DP, Matthews RG, Ludwig ML, Nat Struct Biol. 2002 Jan;9(1):53-6. PMID:11731805
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