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| == Function == | | == Function == |
| [https://www.uniprot.org/uniprot/MEGL_PSEPU MEGL_PSEPU] | | [https://www.uniprot.org/uniprot/MEGL_PSEPU MEGL_PSEPU] |
| <div style="background-color:#fffaf0;">
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| == Publication Abstract from PubMed ==
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| Cys116, Lys240<sup>*</sup>, and Asp241<sup>*</sup> (asterisks indicate residues from the second subunit of the active dimer) at the active site of L-methionine gamma-lyase of Pseudomonas putida (MGL_Pp) are highly conserved among heterologous MGLs. In a previous study, we found that substitution of Cys116 for His led to a drastic increase in activity toward L-cysteine and a decrease in that toward L-methionine. In this study, we examined some properties of the C116H mutant by kinetic analysis and 3D structural analysis. We assumed that substitution of Cys116 for His broke the original hydrogen-bond network and that this induced a significant effect of Tyr114 as a general acid catalyst, possibly due to the narrow space in the active site. The C116H mutant acquired a novel beta-elimination activity and lead a drastic conformation change in the histidine residue at position 116 by binding the substrate, suggesting that this His residue affects the reaction specificity of C116H. Furthermore, we suggest that Lys240<sup>*</sup> is important for substrate recognition and structural stability and that Asp241<sup>*</sup> is also involved in substrate specificity in the elimination reaction. Based on this, we suggest that the hydrogen-bond network among Cys116, Lys240<sup>*</sup>, and Asp241<sup>*</sup> contributes to substrate specificity that is, to L-methionine recognition at the active site in MGL_Pp.
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| The Role of Amino Acid Residues in the Active Site of <small>L</small>-Methionine gamma-lyase from <i>Pseudomonas putida</i>.,Fukumoto M, Kudou D, Murano S, Shiba T, Sato D, Tamura T, Harada S, Inagaki K Biosci Biotechnol Biochem. 2012 Jul 23;76(7):1275-84. Epub 2012 Jul 7. PMID:22785484<ref>PMID:22785484</ref>
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| From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br>
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| </div>
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| <div class="pdbe-citations 3vk4" style="background-color:#fffaf0;"></div>
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| ==See Also== | | ==See Also== |
| *[[Methionine gamma-lyase 3D structures|Methionine gamma-lyase 3D structures]] | | *[[Methionine gamma-lyase 3D structures|Methionine gamma-lyase 3D structures]] |
| == References ==
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| <references/>
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| __TOC__ | | __TOC__ |
| </StructureSection> | | </StructureSection> |
