Protein Phosphatase 2C
From Proteopedia
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|'''Right panel''' - HAB1 (gold), with Mg<sup>2+</sup> and SO<sub>4</sub><sup>2-</sup> in complex with SnRK2.6 (blue) [[3ujg]] | |'''Right panel''' - HAB1 (gold), with Mg<sup>2+</sup> and SO<sub>4</sub><sup>2-</sup> in complex with SnRK2.6 (blue) [[3ujg]] | ||
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| - | | <applet load='3ujk' size='300' frame='true' align='left' caption='3ujk - ABI1' scene = '56/564064/Abi1/1'/><br clear='both'>'''3ujk scenes''' <Br><scene name='56/564064/Abi1/1'>1. Default Scene</scene><br>< | + | | <applet load='3ujk' size='300' frame='true' align='left' caption='3ujk - ABI1' scene = '56/564064/Abi1/1'/><br clear='both'>'''3ujk scenes''' <Br><scene name='56/564064/Abi1/1'>1. Default Scene</scene> PP2Cs have two central antiparallel beta sheets that are flanked by alpha helices. Three magnesium ions (green spheres) occupy the active site.<br><scene name='56/564064/Abi1/5'>2. Active site</scene> is located at one end of the beta sheet sandwich. The arginine residue that binds the phosphate removed from the substrate is shown in blue ball and stick.<br><scene name='56/564064/Abi1/6'>3. Magnesium ions</scene> are coordinated by oxygen atoms from water (small red spheres) and side chains of conserved glutamate and aspartate residues (CPK ball and stick). An unconserved methionine residue in ABI2 (contains yellow sulfur atom) also binds a magnesium ion. A water molecule that bridges the magnesium ions is thought the nucleophile in the SN2 dephosphorylation mechanism. <br><br><br><br><br><br><br><br><br><br><br><br> |
|<applet load='3ujl' size='300' frame='true' align='left' caption='3ujl - PYR2-HAB1' scene = '56/564059/Pyl2hab1/2' /><Br clear='both'>'''3ujl scenes'''<Br><scene name='56/564059/Pyl2hab1/1'>1. Default scene</scene> Complex between PYL2 (blue) with bound ABA (CPK spheres)and HAB1 (gold), a protein phosphatase 2C. Magnesium ions in the active site of HAB1 are shown as green spheres. <br><scene name='56/564059/Pyl2hab1/5'>2. Closed gate locked by interaction with HAB1</scene> Gate residue proline 92 (blue ball and stick) interacts with typtophan 290 (gold ball and stick and residues in a hydrophobic loop (dark gold ball and stick) of HAB1. The gate also interacts with residues surrounding the phosphatase's active site, which is marked by magnesium ions (small green spheres).<br><br><br><br><br><br><br><br><br><br><br><br><br><br> | |<applet load='3ujl' size='300' frame='true' align='left' caption='3ujl - PYR2-HAB1' scene = '56/564059/Pyl2hab1/2' /><Br clear='both'>'''3ujl scenes'''<Br><scene name='56/564059/Pyl2hab1/1'>1. Default scene</scene> Complex between PYL2 (blue) with bound ABA (CPK spheres)and HAB1 (gold), a protein phosphatase 2C. Magnesium ions in the active site of HAB1 are shown as green spheres. <br><scene name='56/564059/Pyl2hab1/5'>2. Closed gate locked by interaction with HAB1</scene> Gate residue proline 92 (blue ball and stick) interacts with typtophan 290 (gold ball and stick and residues in a hydrophobic loop (dark gold ball and stick) of HAB1. The gate also interacts with residues surrounding the phosphatase's active site, which is marked by magnesium ions (small green spheres).<br><br><br><br><br><br><br><br><br><br><br><br><br><br> | ||
| <applet load='3ujg' size='300' frame='true' align='left' caption='3ujg - SnRK2.6-HAB1' scene = '55/559985/Aposnrk2_6/2' /><Br clear='both'>'''3ujg scenes'''<Br><scene name='55/559985/Aposnrk2_6/2'>1. Default Scene</scene> The two enzymes are bound via interface their active sites. The phosphatase inactivates the kinase by dephosphorylating the kinase activation loop and by sterically blocking the kinase active site. The complex was constructed as a fusion protein with a 6His-tag at the N-terminus of SnRK2.6 (residues 11–362) fused to HAB1(172–511) via a GSGSAGSAAGS linker. Mutations of D296A and E297A in SnRK2.6 were introduced at the crystal packing interface to reduce surface entropy. <br><scene name='55/559985/Ost1hab1_interaction/2'>3. Zone of interaction</scene> The activation loop (blue trace) of SnRK2.6 is inserted into the catalytic site (marked by the magnesium ions) of the phosphatase. The phosphorylatable residue of the activation loop S175 (CPK ball and stick) is positioned near the magnesium ions. W385 of the phosphatase (brown ball and stick) in turn protrudes into the kinase's active site, where it interacts with residues R139 and Glu144 (CPK ball and stick) of the catalytic loop (orchid trace) and I183 of the activation loop.<br><scene name='55/559985/Tetherbinding/1'> 5. Proposed interaction zone </scene> SnRK2.6 is shown in blue cartoon, and HAB1 in gold spacefill. The ABA box sequence is not resolved, but it would extend from the C-terminal end of the SNRK2 box helix (cyan helix). It is proposed that the ABA box sequence, which is highly acidic, binds to a patch of basic residues (blue) on the surface of the phosphatase.<ref name ="Soon2012"> PMID:22116026 </ref> | | <applet load='3ujg' size='300' frame='true' align='left' caption='3ujg - SnRK2.6-HAB1' scene = '55/559985/Aposnrk2_6/2' /><Br clear='both'>'''3ujg scenes'''<Br><scene name='55/559985/Aposnrk2_6/2'>1. Default Scene</scene> The two enzymes are bound via interface their active sites. The phosphatase inactivates the kinase by dephosphorylating the kinase activation loop and by sterically blocking the kinase active site. The complex was constructed as a fusion protein with a 6His-tag at the N-terminus of SnRK2.6 (residues 11–362) fused to HAB1(172–511) via a GSGSAGSAAGS linker. Mutations of D296A and E297A in SnRK2.6 were introduced at the crystal packing interface to reduce surface entropy. <br><scene name='55/559985/Ost1hab1_interaction/2'>3. Zone of interaction</scene> The activation loop (blue trace) of SnRK2.6 is inserted into the catalytic site (marked by the magnesium ions) of the phosphatase. The phosphorylatable residue of the activation loop S175 (CPK ball and stick) is positioned near the magnesium ions. W385 of the phosphatase (brown ball and stick) in turn protrudes into the kinase's active site, where it interacts with residues R139 and Glu144 (CPK ball and stick) of the catalytic loop (orchid trace) and I183 of the activation loop.<br><scene name='55/559985/Tetherbinding/1'> 5. Proposed interaction zone </scene> SnRK2.6 is shown in blue cartoon, and HAB1 in gold spacefill. The ABA box sequence is not resolved, but it would extend from the C-terminal end of the SNRK2 box helix (cyan helix). It is proposed that the ABA box sequence, which is highly acidic, binds to a patch of basic residues (blue) on the surface of the phosphatase.<ref name ="Soon2012"> PMID:22116026 </ref> | ||
Revision as of 14:10, 11 October 2013
Contents |
This page is under construction
Five plant protein phosphatase 2Cs are essential components of the core ABA Signaling Pathway[1][2][3].
| Left panel - ABI1 3ujk | Middle panel- HAB1 bound to PYL2.ABA 3ujl | Right panel - HAB1 (gold), with Mg2+ and SO42- in complex with SnRK2.6 (blue) 3ujg | ||||||||||||||||||
3ujk scenes PP2Cs have two central antiparallel beta sheets that are flanked by alpha helices. Three magnesium ions (green spheres) occupy the active site. is located at one end of the beta sheet sandwich. The arginine residue that binds the phosphate removed from the substrate is shown in blue ball and stick. are coordinated by oxygen atoms from water (small red spheres) and side chains of conserved glutamate and aspartate residues (CPK ball and stick). An unconserved methionine residue in ABI2 (contains yellow sulfur atom) also binds a magnesium ion. A water molecule that bridges the magnesium ions is thought the nucleophile in the SN2 dephosphorylation mechanism. |
3ujl scenes Complex between PYL2 (blue) with bound ABA (CPK spheres)and HAB1 (gold), a protein phosphatase 2C. Magnesium ions in the active site of HAB1 are shown as green spheres. Gate residue proline 92 (blue ball and stick) interacts with typtophan 290 (gold ball and stick and residues in a hydrophobic loop (dark gold ball and stick) of HAB1. The gate also interacts with residues surrounding the phosphatase's active site, which is marked by magnesium ions (small green spheres). |
3ujg scenes The two enzymes are bound via interface their active sites. The phosphatase inactivates the kinase by dephosphorylating the kinase activation loop and by sterically blocking the kinase active site. The complex was constructed as a fusion protein with a 6His-tag at the N-terminus of SnRK2.6 (residues 11–362) fused to HAB1(172–511) via a GSGSAGSAAGS linker. Mutations of D296A and E297A in SnRK2.6 were introduced at the crystal packing interface to reduce surface entropy. The activation loop (blue trace) of SnRK2.6 is inserted into the catalytic site (marked by the magnesium ions) of the phosphatase. The phosphorylatable residue of the activation loop S175 (CPK ball and stick) is positioned near the magnesium ions. W385 of the phosphatase (brown ball and stick) in turn protrudes into the kinase's active site, where it interacts with residues R139 and Glu144 (CPK ball and stick) of the catalytic loop (orchid trace) and I183 of the activation loop. SnRK2.6 is shown in blue cartoon, and HAB1 in gold spacefill. The ABA box sequence is not resolved, but it would extend from the C-terminal end of the SNRK2 box helix (cyan helix). It is proposed that the ABA box sequence, which is highly acidic, binds to a patch of basic residues (blue) on the surface of the phosphatase.[4] |
ABA-regulated PP2C structures
3jrq, 3kdj, 3nmn – AtPP2C (ABI1) + Pyl1 – Arabidopsis thaliana
3nmt, 3kb3, 3nmv, 3ujl – AtPP2C (HAB1)+ Pyl2
4ds8 – AtPP2C (HAB1) + Pyl3 + Mn
3rt0 – AtPP2C (mutant) (HAB1) + Pyl10
3qn1, 3zvu – AtPP2C (HAB1)+ Pyr1
3ujg – AtPP2C (HAB1)+ SNRK2
3ujk – AtPP2C
References
- ↑ Ma Y, Szostkiewicz I, Korte A, Moes D, Yang Y, Christmann A, Grill E. Regulators of PP2C phosphatase activity function as abscisic acid sensors. Science. 2009 May 22;324(5930):1064-8. doi: 10.1126/science.1172408. Epub 2009, Apr 30. PMID:19407143 doi:10.1126/science.1172408
- ↑ Park SY, Fung P, Nishimura N, Jensen DR, Fujii H, Zhao Y, Lumba S, Santiago J, Rodrigues A, Chow TF, Alfred SE, Bonetta D, Finkelstein R, Provart NJ, Desveaux D, Rodriguez PL, McCourt P, Zhu JK, Schroeder JI, Volkman BF, Cutler SR. Abscisic acid inhibits type 2C protein phosphatases via the PYR/PYL family of START proteins. Science. 2009 May 22;324(5930):1068-71. doi: 10.1126/science.1173041. Epub 2009, Apr 30. PMID:19407142 doi:10.1126/science.1173041
- ↑ Yoshida T, Nishimura N, Kitahata N, Kuromori T, Ito T, Asami T, Shinozaki K, Hirayama T. ABA-hypersensitive germination3 encodes a protein phosphatase 2C (AtPP2CA) that strongly regulates abscisic acid signaling during germination among Arabidopsis protein phosphatase 2Cs. Plant Physiol. 2006 Jan;140(1):115-26. Epub 2005 Dec 9. PMID:16339800 doi:10.1104/pp.105.070128
- ↑ Soon FF, Ng LM, Zhou XE, West GM, Kovach A, Tan MH, Suino-Powell KM, He Y, Xu Y, Chalmers MJ, Brunzelle JS, Zhang H, Yang H, Jiang H, Li J, Yong EL, Cutler S, Zhu JK, Griffin PR, Melcher K, Xu HE. Molecular mimicry regulates ABA signaling by SnRK2 kinases and PP2C phosphatases. Science. 2012 Jan 6;335(6064):85-8. Epub 2011 Nov 24. PMID:22116026 doi:10.1126/science.1215106
See Also
[1] Abscisic Acid in Wikipedia
Proteopedia Page Contributors and Editors (what is this?)
Alice Harmon, Alexsandra Tifane Santos do Nascimento, Michal Harel, Jaime Prilusky
