2o2k
From Proteopedia
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| - | [[Image:2o2k.gif|left|200px]] | ||
| - | + | ==Crystal Structure of the Activation Domain of Human Methionine Synthase Isoform/Mutant D963E/K1071N== | |
| - | + | <StructureSection load='2o2k' size='340' side='right'caption='[[2o2k]], [[Resolution|resolution]] 1.60Å' scene=''> | |
| - | + | == Structural highlights == | |
| - | + | <table><tr><td colspan='2'>[[2o2k]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2O2K OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2O2K FirstGlance]. <br> | |
| - | + | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.6Å</td></tr> | |
| - | + | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=2o2k FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2o2k OCA], [https://pdbe.org/2o2k PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2o2k RCSB], [https://www.ebi.ac.uk/pdbsum/2o2k PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2o2k ProSAT]</span></td></tr> | |
| - | + | </table> | |
| - | + | == Disease == | |
| - | + | [https://www.uniprot.org/uniprot/METH_HUMAN METH_HUMAN] Defects in MTR are the cause of methylcobalamin deficiency type G (cblG) [MIM:[https://omim.org/entry/250940 250940]; also known as homocystinuria-megaloblastic anemia complementation type G. It is an autosomal recessive inherited disease that causes mental retardation, macrocytic anemia, and homocystinuria. Mild deficiency in MS activity could be associated with mild hyperhomocysteinemia, a risk factor for cardiovascular disease and possibly neural tube defects. MS mutations could also be involved in tumorigenesis. Defects in MTR may be a cause of susceptibility to folate-sensitive neural tube defects (FS-NTD) [MIM:[https://omim.org/entry/601634 601634]. The most common NTDs are open spina bifida (myelomeningocele) and anencephaly. Genetic defects in MTR may affect the risk of spina bifida via the maternal rather than the embryonic genotype.<ref>PMID:12375236</ref> <ref>PMID:15979034</ref> | |
| - | + | == Function == | |
| - | + | [https://www.uniprot.org/uniprot/METH_HUMAN METH_HUMAN] Catalyzes the transfer of a methyl group from methyl-cobalamin to homocysteine, yielding enzyme-bound cob(I)alamin and methionine. Subsequently, remethylates the cofactor using methyltetrahydrofolate (By similarity). | |
| - | + | == Evolutionary Conservation == | |
| - | + | [[Image:Consurf_key_small.gif|200px|right]] | |
| - | + | Check<jmol> | |
| - | == | + | <jmolCheckbox> |
| + | <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/o2/2o2k_consurf.spt"</scriptWhenChecked> | ||
| + | <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked> | ||
| + | <text>to colour the structure by Evolutionary Conservation</text> | ||
| + | </jmolCheckbox> | ||
| + | </jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=2o2k ConSurf]. | ||
| + | <div style="clear:both"></div> | ||
| + | <div style="background-color:#fffaf0;"> | ||
| + | == Publication Abstract from PubMed == | ||
Human methionine synthase (hMS) is a multidomain cobalamin-dependent enzyme that catalyses the conversion of homocysteine to methionine by methyl group transfer. We report here the 1.6 A crystal structure of the C-terminal activation domain of hMS. The structure is C-shaped with the core comprising mixed alpha and beta regions, dominated by a twisted antiparallel beta sheet with a beta-meander region. These features, including the positions of the active-site residues, are similar to the activation domain of Escherichia coli cobalamin-dependent MS (MetH). Structural and solution studies suggest a small proportion of hMS activation domain exists in a dimeric form, which contrasts with the monomeric form of the E. coli homologue. Fluorescence studies show that human activation domain interacts with the FMN-binding domain of human methionine synthase reductase (hMSR). This interaction is enhanced in the presence of S-adenosyl-methionine. Binding of the D963E/K1071N mutant activation domain to the FMN domain of MSR is weaker than with wild-type activation domain. This suggests that one or both of the residues D963 and K1071 are important in partner binding. Key differences in the sequences and structures of hMS and MetH activation domains are recognized and include a major reorientation of an extended 3(10)-containing loop in the human protein. This structural alteration might reflect differences in their respective reactivation complexes and/or potential for dimer formation. The reported structure is a component of the multidomain hMS : MSR complex, and represents an important step in understanding the impact of clinical mutations and polymorphisms in this key electron transfer complex. | Human methionine synthase (hMS) is a multidomain cobalamin-dependent enzyme that catalyses the conversion of homocysteine to methionine by methyl group transfer. We report here the 1.6 A crystal structure of the C-terminal activation domain of hMS. The structure is C-shaped with the core comprising mixed alpha and beta regions, dominated by a twisted antiparallel beta sheet with a beta-meander region. These features, including the positions of the active-site residues, are similar to the activation domain of Escherichia coli cobalamin-dependent MS (MetH). Structural and solution studies suggest a small proportion of hMS activation domain exists in a dimeric form, which contrasts with the monomeric form of the E. coli homologue. Fluorescence studies show that human activation domain interacts with the FMN-binding domain of human methionine synthase reductase (hMSR). This interaction is enhanced in the presence of S-adenosyl-methionine. Binding of the D963E/K1071N mutant activation domain to the FMN domain of MSR is weaker than with wild-type activation domain. This suggests that one or both of the residues D963 and K1071 are important in partner binding. Key differences in the sequences and structures of hMS and MetH activation domains are recognized and include a major reorientation of an extended 3(10)-containing loop in the human protein. This structural alteration might reflect differences in their respective reactivation complexes and/or potential for dimer formation. The reported structure is a component of the multidomain hMS : MSR complex, and represents an important step in understanding the impact of clinical mutations and polymorphisms in this key electron transfer complex. | ||
| - | + | Crystal structure and solution characterization of the activation domain of human methionine synthase.,Wolthers KR, Toogood HS, Jowitt TA, Marshall KR, Leys D, Scrutton NS FEBS J. 2007 Feb;274(3):738-50. PMID:17288554<ref>PMID:17288554</ref> | |
| - | + | ||
| - | + | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |
| - | + | </div> | |
| + | <div class="pdbe-citations 2o2k" style="background-color:#fffaf0;"></div> | ||
| - | == | + | ==See Also== |
| - | + | *[[Methionine synthase 3D structures|Methionine synthase 3D structures]] | |
| + | == References == | ||
| + | <references/> | ||
| + | __TOC__ | ||
| + | </StructureSection> | ||
[[Category: Homo sapiens]] | [[Category: Homo sapiens]] | ||
| - | [[Category: | + | [[Category: Large Structures]] |
| - | + | [[Category: Jowitt TA]] | |
| - | [[Category: Jowitt | + | [[Category: Leys D]] |
| - | [[Category: Leys | + | [[Category: Marshall KR]] |
| - | [[Category: Marshall | + | [[Category: Scrutton NS]] |
| - | [[Category: Scrutton | + | [[Category: Toogood HS]] |
| - | [[Category: Toogood | + | [[Category: Wolthers KR]] |
| - | [[Category: Wolthers | + | |
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Current revision
Crystal Structure of the Activation Domain of Human Methionine Synthase Isoform/Mutant D963E/K1071N
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