3b5i
From Proteopedia
(New page: 200px<br /><applet load="3b5i" size="350" color="white" frame="true" align="right" spinBox="true" caption="3b5i, resolution 2.75Å" /> '''Crystal structure of...) |
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==Overview== | ==Overview== | ||
| - | The plant SABATH protein family encompasses a group of related small | + | The plant SABATH protein family encompasses a group of related small-molecule methyltransferases (MTs) that catalyze the S-adenosyl-l-methionine-dependent methylation of natural chemicals encompassing widely divergent structures. Indole-3-acetic acid (IAA) methyltransferase (IAMT) is a member of the SABATH family that modulates IAA homeostasis in plant tissues through methylation of IAA's free carboxyl group. The crystal structure of Arabidopsis (Arabidopsis thaliana) IAMT (AtIAMT1) was determined and refined to 2.75 A resolution. The overall tertiary and quaternary structures closely resemble the two-domain bilobed monomer and the dimeric arrangement, respectively, previously observed for the related salicylic acid carboxyl methyltransferase from Clarkia breweri (CbSAMT). To further our understanding of the biological function and evolution of SABATHs, especially of IAMT, we analyzed the SABATH gene family in the rice (Oryza sativa) genome. Forty-one OsSABATH genes were identified. Expression analysis showed that more than one-half of the OsSABATH genes were transcribed in one or multiple organs. The OsSABATH gene most similar to AtIAMT1 is OsSABATH4. Escherichia coli-expressed OsSABATH4 protein displayed the highest level of catalytic activity toward IAA and was therefore named OsIAMT1. OsIAMT1 exhibited kinetic properties similar to AtIAMT1 and poplar IAMT (PtIAMT1). Structural modeling of OsIAMT1 and PtIAMT1 using the experimentally determined structure of AtIAMT1 reported here as a template revealed conserved structural features of IAMTs within the active-site cavity that are divergent from functionally distinct members of the SABATH family, such as CbSAMT. Phylogenetic analysis revealed that IAMTs from Arabidopsis, rice, and poplar (Populus spp.) form a monophyletic group. Thus, structural, biochemical, and phylogenetic evidence supports the hypothesis that IAMT is an evolutionarily ancient member of the SABATH family likely to play a critical role in IAA homeostasis across a wide range of plants. |
==About this Structure== | ==About this Structure== | ||
| - | 3B5I is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Arabidopsis_thaliana Arabidopsis thaliana] with <scene name='pdbligand=MG:'>MG</scene> and <scene name='pdbligand=SAH:'>SAH</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3B5I OCA]. | + | 3B5I is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Arabidopsis_thaliana Arabidopsis thaliana] with <scene name='pdbligand=MG:'>MG</scene> and <scene name='pdbligand=SAH:'>SAH</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Known structural/functional Sites: <scene name='pdbsite=AC1:Mg+Binding+Site+For+Residue+A+601'>AC1</scene>, <scene name='pdbsite=AC2:Mg+Binding+Site+For+Residue+B+601'>AC2</scene>, <scene name='pdbsite=AC3:Sah+Binding+Site+For+Residue+A+401'>AC3</scene> and <scene name='pdbsite=AC4:Sah+Binding+Site+For+Residue+B+401'>AC4</scene>. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3B5I OCA]. |
==Reference== | ==Reference== | ||
| - | Structural, Biochemical and Phylogenetic Analyses Suggest | + | Structural, Biochemical, and Phylogenetic Analyses Suggest That Indole-3-Acetic Acid Methyltransferase Is an Evolutionarily Ancient Member of the SABATH Family., Zhao N, Ferrer JL, Ross J, Guan J, Yang Y, Pichersky E, Noel JP, Chen F, Plant Physiol. 2008 Feb;146(2):455-67. Epub 2007 Dec 27. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=18162595 18162595] |
[[Category: Arabidopsis thaliana]] | [[Category: Arabidopsis thaliana]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Ferrer, J | + | [[Category: Ferrer, J L.]] |
| - | [[Category: Noel, J | + | [[Category: Noel, J P.]] |
[[Category: MG]] | [[Category: MG]] | ||
[[Category: SAH]] | [[Category: SAH]] | ||
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[[Category: sabath family]] | [[Category: sabath family]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 19:03:26 2008'' |
Revision as of 17:03, 21 February 2008
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Crystal structure of Indole-3-acetic Acid Methyltransferase
Overview
The plant SABATH protein family encompasses a group of related small-molecule methyltransferases (MTs) that catalyze the S-adenosyl-l-methionine-dependent methylation of natural chemicals encompassing widely divergent structures. Indole-3-acetic acid (IAA) methyltransferase (IAMT) is a member of the SABATH family that modulates IAA homeostasis in plant tissues through methylation of IAA's free carboxyl group. The crystal structure of Arabidopsis (Arabidopsis thaliana) IAMT (AtIAMT1) was determined and refined to 2.75 A resolution. The overall tertiary and quaternary structures closely resemble the two-domain bilobed monomer and the dimeric arrangement, respectively, previously observed for the related salicylic acid carboxyl methyltransferase from Clarkia breweri (CbSAMT). To further our understanding of the biological function and evolution of SABATHs, especially of IAMT, we analyzed the SABATH gene family in the rice (Oryza sativa) genome. Forty-one OsSABATH genes were identified. Expression analysis showed that more than one-half of the OsSABATH genes were transcribed in one or multiple organs. The OsSABATH gene most similar to AtIAMT1 is OsSABATH4. Escherichia coli-expressed OsSABATH4 protein displayed the highest level of catalytic activity toward IAA and was therefore named OsIAMT1. OsIAMT1 exhibited kinetic properties similar to AtIAMT1 and poplar IAMT (PtIAMT1). Structural modeling of OsIAMT1 and PtIAMT1 using the experimentally determined structure of AtIAMT1 reported here as a template revealed conserved structural features of IAMTs within the active-site cavity that are divergent from functionally distinct members of the SABATH family, such as CbSAMT. Phylogenetic analysis revealed that IAMTs from Arabidopsis, rice, and poplar (Populus spp.) form a monophyletic group. Thus, structural, biochemical, and phylogenetic evidence supports the hypothesis that IAMT is an evolutionarily ancient member of the SABATH family likely to play a critical role in IAA homeostasis across a wide range of plants.
About this Structure
3B5I is a Single protein structure of sequence from Arabidopsis thaliana with and as ligands. Known structural/functional Sites: , , and . Full crystallographic information is available from OCA.
Reference
Structural, Biochemical, and Phylogenetic Analyses Suggest That Indole-3-Acetic Acid Methyltransferase Is an Evolutionarily Ancient Member of the SABATH Family., Zhao N, Ferrer JL, Ross J, Guan J, Yang Y, Pichersky E, Noel JP, Chen F, Plant Physiol. 2008 Feb;146(2):455-67. Epub 2007 Dec 27. PMID:18162595
Page seeded by OCA on Thu Feb 21 19:03:26 2008
