1k7h
From Proteopedia
(New page: 200px<br /><applet load="1k7h" size="450" color="white" frame="true" align="right" spinBox="true" caption="1k7h, resolution 1.92Å" /> '''CRYSTAL STRUCTURE OF...) |
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| - | [[Image:1k7h.jpg|left|200px]]<br /><applet load="1k7h" size=" | + | [[Image:1k7h.jpg|left|200px]]<br /><applet load="1k7h" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1k7h, resolution 1.92Å" /> | caption="1k7h, resolution 1.92Å" /> | ||
'''CRYSTAL STRUCTURE OF SHRIMP ALKALINE PHOSPHATASE'''<br /> | '''CRYSTAL STRUCTURE OF SHRIMP ALKALINE PHOSPHATASE'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Alkaline phosphatases are non-specific phosphomonoesterases that are | + | Alkaline phosphatases are non-specific phosphomonoesterases that are distributed widely in species ranging from bacteria to man. This study has concentrated on the tissue-nonspecific alkaline phosphatase from arctic shrimps (shrimp alkaline phosphatase, SAP). Originating from a cold-active species, SAP is thermolabile and is used widely in vitro, e.g. to dephosphorylate DNA or dNTPs, since it can be inactivated by a short rise in temperature. Since alkaline phosphatases are zinc-containing enzymes, a multiwavelength anomalous dispersion (MAD) experiment was performed on the zinc K edge, which led to the determination of the structure to a resolution of 1.9 A. Anomalous data clearly showed the presence of a zinc triad in the active site, whereas alkaline phosphatases usually contain two zinc and one magnesium ion per monomer. SAP shares the core, an extended beta-sheet flanked by alpha-helices, and a metal triad with the currently known alkaline phosphatase structures (Escherichia coli structures and a human placental structure). Although SAP lacks some features specific for the mammalian enzyme, their backbones are very similar and may therefore be typical for other higher organisms. Furthermore, SAP possesses a striking feature that the other structures lack: surface potential representations show that the enzyme's net charge of -80 is distributed such that the surface is predominantly negatively charged, except for the positively charged active site. The negatively charged substrate must therefore be directed strongly towards the active site. It is generally accepted that optimization of the electrostatics is one of the characteristics related to cold-adaptation. SAP demonstrates this principle very clearly. |
==About this Structure== | ==About this Structure== | ||
| - | 1K7H is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Pandalus_borealis Pandalus borealis] with NAG, ZN, SO4 and MAE as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Alkaline_phosphatase Alkaline phosphatase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.1.3.1 3.1.3.1] Full crystallographic information is available from [http:// | + | 1K7H is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Pandalus_borealis Pandalus borealis] with <scene name='pdbligand=NAG:'>NAG</scene>, <scene name='pdbligand=ZN:'>ZN</scene>, <scene name='pdbligand=SO4:'>SO4</scene> and <scene name='pdbligand=MAE:'>MAE</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Alkaline_phosphatase Alkaline phosphatase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.1.3.1 3.1.3.1] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1K7H OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Pandalus borealis]] | [[Category: Pandalus borealis]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Backer, M | + | [[Category: Backer, M E.De.]] |
[[Category: Hough, E.]] | [[Category: Hough, E.]] | ||
[[Category: Lindley, P.]] | [[Category: Lindley, P.]] | ||
| - | [[Category: Rasmussen, H | + | [[Category: Rasmussen, H B.]] |
| - | [[Category: Riise, B | + | [[Category: Riise, B W.]] |
| - | [[Category: Sweeney, S | + | [[Category: Sweeney, S Mc.]] |
[[Category: MAE]] | [[Category: MAE]] | ||
[[Category: NAG]] | [[Category: NAG]] | ||
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[[Category: zinc triad]] | [[Category: zinc triad]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:31:01 2008'' |
Revision as of 11:31, 21 February 2008
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CRYSTAL STRUCTURE OF SHRIMP ALKALINE PHOSPHATASE
Overview
Alkaline phosphatases are non-specific phosphomonoesterases that are distributed widely in species ranging from bacteria to man. This study has concentrated on the tissue-nonspecific alkaline phosphatase from arctic shrimps (shrimp alkaline phosphatase, SAP). Originating from a cold-active species, SAP is thermolabile and is used widely in vitro, e.g. to dephosphorylate DNA or dNTPs, since it can be inactivated by a short rise in temperature. Since alkaline phosphatases are zinc-containing enzymes, a multiwavelength anomalous dispersion (MAD) experiment was performed on the zinc K edge, which led to the determination of the structure to a resolution of 1.9 A. Anomalous data clearly showed the presence of a zinc triad in the active site, whereas alkaline phosphatases usually contain two zinc and one magnesium ion per monomer. SAP shares the core, an extended beta-sheet flanked by alpha-helices, and a metal triad with the currently known alkaline phosphatase structures (Escherichia coli structures and a human placental structure). Although SAP lacks some features specific for the mammalian enzyme, their backbones are very similar and may therefore be typical for other higher organisms. Furthermore, SAP possesses a striking feature that the other structures lack: surface potential representations show that the enzyme's net charge of -80 is distributed such that the surface is predominantly negatively charged, except for the positively charged active site. The negatively charged substrate must therefore be directed strongly towards the active site. It is generally accepted that optimization of the electrostatics is one of the characteristics related to cold-adaptation. SAP demonstrates this principle very clearly.
About this Structure
1K7H is a Single protein structure of sequence from Pandalus borealis with , , and as ligands. Active as Alkaline phosphatase, with EC number 3.1.3.1 Full crystallographic information is available from OCA.
Reference
The 1.9 A crystal structure of heat-labile shrimp alkaline phosphatase., de Backer M, McSweeney S, Rasmussen HB, Riise BW, Lindley P, Hough E, J Mol Biol. 2002 May 17;318(5):1265-74. PMID:12083516
Page seeded by OCA on Thu Feb 21 13:31:01 2008
Categories: Alkaline phosphatase | Pandalus borealis | Single protein | Backer, M E.De. | Hough, E. | Lindley, P. | Rasmussen, H B. | Riise, B W. | Sweeney, S Mc. | MAE | NAG | SO4 | ZN | Extended beta sheet | Hydrolase | Metal triad | Phosphomonoester | Transferase | Zinc triad
