1u32
From Proteopedia
(New page: 200px<br /> <applet load="1u32" size="450" color="white" frame="true" align="right" spinBox="true" caption="1u32, resolution 2.00Å" /> '''Crystal structure o...) |
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caption="1u32, resolution 2.00Å" /> | caption="1u32, resolution 2.00Å" /> | ||
'''Crystal structure of a Protein Phosphatase-1: Calcineurin Hybrid Bound to Okadaic Acid'''<br /> | '''Crystal structure of a Protein Phosphatase-1: Calcineurin Hybrid Bound to Okadaic Acid'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Protein phosphatase-1 and protein phosphatase-2B (calcineurin) are | + | Protein phosphatase-1 and protein phosphatase-2B (calcineurin) are eukaryotic serine/threonine phosphatases that share 40% sequence identity in their catalytic subunits. Despite the similarities in sequence, these phosphatases are widely divergent when it comes to inhibition by natural product toxins, such as microcystin-LR and okadaic acid. The most prominent region of non-conserved sequence between these phosphatases corresponds to the beta12-beta13 loop of protein phosphatase-1, and the L7 loop of toxin-resistant calcineurin. In the present study, mutagenesis of residues 273-277 of the beta12-beta13 loop of the protein phosphatase-1 catalytic subunit (PP-1c) to the corresponding residues in calcineurin (312-316), resulted in a chimeric mutant that showed a decrease in sensitivity to microcystin-LR, okadaic acid, and the endogenous PP-1c inhibitor protein inhibitor-2. A crystal structure of the chimeric mutant in complex with okadaic acid was determined to 2.0-A resolution. The beta12-beta13 loop region of the mutant superimposes closely with that of wild-type PP-1c bound to okadaic acid. Systematic mutation of each residue in the beta12-beta13 loop of PP-1c showed that a single amino acid change (C273L) was the most influential in mediating sensitivity of PP-1c to toxins. Taken together, these data indicate that it is an individual amino acid residue substitution and not a change in the overall beta12-beta13 loop conformation of protein phosphatase-1 that contributes to disrupting important interactions with inhibitors such as microcystin-LR and okadaic acid. |
==About this Structure== | ==About this Structure== | ||
| - | 1U32 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] with MN, OKA and BME as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Phosphoprotein_phosphatase Phosphoprotein phosphatase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.1.3.16 3.1.3.16] Full crystallographic information is available from [http:// | + | 1U32 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] with <scene name='pdbligand=MN:'>MN</scene>, <scene name='pdbligand=OKA:'>OKA</scene> and <scene name='pdbligand=BME:'>BME</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Phosphoprotein_phosphatase Phosphoprotein phosphatase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.1.3.16 3.1.3.16] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1U32 OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Phosphoprotein phosphatase]] | [[Category: Phosphoprotein phosphatase]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Cherney, M | + | [[Category: Cherney, M M.]] |
| - | [[Category: Holmes, C | + | [[Category: Holmes, C F.B.]] |
| - | [[Category: James, M | + | [[Category: James, M N.G.]] |
| - | [[Category: Luu, H | + | [[Category: Luu, H A.]] |
| - | [[Category: Maynes, J | + | [[Category: Maynes, J T.]] |
| - | [[Category: Perreault, K | + | [[Category: Perreault, K R.]] |
[[Category: BME]] | [[Category: BME]] | ||
[[Category: MN]] | [[Category: MN]] | ||
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[[Category: hydrolase]] | [[Category: hydrolase]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:20:07 2008'' |
Revision as of 13:20, 21 February 2008
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Crystal structure of a Protein Phosphatase-1: Calcineurin Hybrid Bound to Okadaic Acid
Overview
Protein phosphatase-1 and protein phosphatase-2B (calcineurin) are eukaryotic serine/threonine phosphatases that share 40% sequence identity in their catalytic subunits. Despite the similarities in sequence, these phosphatases are widely divergent when it comes to inhibition by natural product toxins, such as microcystin-LR and okadaic acid. The most prominent region of non-conserved sequence between these phosphatases corresponds to the beta12-beta13 loop of protein phosphatase-1, and the L7 loop of toxin-resistant calcineurin. In the present study, mutagenesis of residues 273-277 of the beta12-beta13 loop of the protein phosphatase-1 catalytic subunit (PP-1c) to the corresponding residues in calcineurin (312-316), resulted in a chimeric mutant that showed a decrease in sensitivity to microcystin-LR, okadaic acid, and the endogenous PP-1c inhibitor protein inhibitor-2. A crystal structure of the chimeric mutant in complex with okadaic acid was determined to 2.0-A resolution. The beta12-beta13 loop region of the mutant superimposes closely with that of wild-type PP-1c bound to okadaic acid. Systematic mutation of each residue in the beta12-beta13 loop of PP-1c showed that a single amino acid change (C273L) was the most influential in mediating sensitivity of PP-1c to toxins. Taken together, these data indicate that it is an individual amino acid residue substitution and not a change in the overall beta12-beta13 loop conformation of protein phosphatase-1 that contributes to disrupting important interactions with inhibitors such as microcystin-LR and okadaic acid.
About this Structure
1U32 is a Single protein structure of sequence from Homo sapiens with , and as ligands. Active as Phosphoprotein phosphatase, with EC number 3.1.3.16 Full crystallographic information is available from OCA.
Reference
Crystal structure and mutagenesis of a protein phosphatase-1:calcineurin hybrid elucidate the role of the beta12-beta13 loop in inhibitor binding., Maynes JT, Perreault KR, Cherney MM, Luu HA, James MN, Holmes CF, J Biol Chem. 2004 Oct 8;279(41):43198-206. Epub 2004 Jul 26. PMID:15280359
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