1xc4
From Proteopedia
(New page: 200px<br /><applet load="1xc4" size="450" color="white" frame="true" align="right" spinBox="true" caption="1xc4, resolution 2.8Å" /> '''Crystal structure of ...) |
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| - | [[Image:1xc4.jpg|left|200px]]<br /><applet load="1xc4" size=" | + | [[Image:1xc4.jpg|left|200px]]<br /><applet load="1xc4" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1xc4, resolution 2.8Å" /> | caption="1xc4, resolution 2.8Å" /> | ||
'''Crystal structure of wild-type tryptophan synthase alpha-subunits from Escherichia coli'''<br /> | '''Crystal structure of wild-type tryptophan synthase alpha-subunits from Escherichia coli'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The alpha-subunit of tryptophan synthase (alphaTS) catalyzes the cleavage | + | The alpha-subunit of tryptophan synthase (alphaTS) catalyzes the cleavage of indole-3-glycerol phosphate to glyceraldehyde-3-phosphate and indole, which is used to yield the amino acid tryptophan in tryptophan biosynthesis. Here, we report the first crystal structures of wild-type and double-mutant P28L/Y173F alpha-subunit of tryptophan synthase from Escherichia coli at 2.8 and 1.8A resolution, respectively. The structure of wild-type alphaTS from E. coli was similar to that of the alpha(2)beta(2) complex structure from Salmonella typhimurium. As compared with both structures, the conformational changes are mostly in the interface of alpha- and beta-subunits, and the substrate binding region. Two sulfate ions and two glycerol molecules per asymmetric unit bind with the residues in the active sites of the wild-type structure. Contrarily, double-mutant P28L/Y173F structure is highly closed at the window for the substrate binding by the conformational changes. The P28L substitution induces the exposure of hydrophobic amino acids and decreases the secondary structure that causes the aggregation. The Y173F suppresses to transfer a signal from the alpha-subunit core to the alpha-subunit surface involved in interactions with the beta-subunit and increases structural stability. |
==About this Structure== | ==About this Structure== | ||
| - | 1XC4 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 GOL as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Tryptophan_synthase Tryptophan synthase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=4.2.1.20 4.2.1.20] Full crystallographic information is available from [http:// | + | 1XC4 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=GOL:'>GOL</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Tryptophan_synthase Tryptophan synthase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=4.2.1.20 4.2.1.20] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1XC4 OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Tryptophan synthase]] | [[Category: Tryptophan synthase]] | ||
| - | [[Category: Jang, S | + | [[Category: Jang, S B.]] |
[[Category: GOL]] | [[Category: GOL]] | ||
[[Category: SO4]] | [[Category: SO4]] | ||
[[Category: a-subunits]] | [[Category: a-subunits]] | ||
| - | [[Category: e | + | [[Category: e coli]] |
[[Category: tryptophan synthase]] | [[Category: tryptophan synthase]] | ||
[[Category: wild-type]] | [[Category: wild-type]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:53:11 2008'' |
Revision as of 13:53, 21 February 2008
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Crystal structure of wild-type tryptophan synthase alpha-subunits from Escherichia coli
Overview
The alpha-subunit of tryptophan synthase (alphaTS) catalyzes the cleavage of indole-3-glycerol phosphate to glyceraldehyde-3-phosphate and indole, which is used to yield the amino acid tryptophan in tryptophan biosynthesis. Here, we report the first crystal structures of wild-type and double-mutant P28L/Y173F alpha-subunit of tryptophan synthase from Escherichia coli at 2.8 and 1.8A resolution, respectively. The structure of wild-type alphaTS from E. coli was similar to that of the alpha(2)beta(2) complex structure from Salmonella typhimurium. As compared with both structures, the conformational changes are mostly in the interface of alpha- and beta-subunits, and the substrate binding region. Two sulfate ions and two glycerol molecules per asymmetric unit bind with the residues in the active sites of the wild-type structure. Contrarily, double-mutant P28L/Y173F structure is highly closed at the window for the substrate binding by the conformational changes. The P28L substitution induces the exposure of hydrophobic amino acids and decreases the secondary structure that causes the aggregation. The Y173F suppresses to transfer a signal from the alpha-subunit core to the alpha-subunit surface involved in interactions with the beta-subunit and increases structural stability.
About this Structure
1XC4 is a Single protein structure of sequence from Escherichia coli with and as ligands. Active as Tryptophan synthase, with EC number 4.2.1.20 Full crystallographic information is available from OCA.
Reference
Structures of wild-type and P28L/Y173F tryptophan synthase alpha-subunits from Escherichia coli., Jeong MS, Jeong JK, Lim WK, Jang SB, Biochem Biophys Res Commun. 2004 Oct 29;323(4):1257-64. PMID:15451433
Page seeded by OCA on Thu Feb 21 15:53:11 2008
Categories: Escherichia coli | Single protein | Tryptophan synthase | Jang, S B. | GOL | SO4 | A-subunits | E coli | Wild-type
