1p6e
From Proteopedia
(New page: 200px<br /><applet load="1p6e" size="450" color="white" frame="true" align="right" spinBox="true" caption="1p6e, resolution 2.3Å" /> '''STRUCTURE OF THE D55N...) |
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| - | [[Image:1p6e.jpg|left|200px]]<br /><applet load="1p6e" size=" | + | [[Image:1p6e.jpg|left|200px]]<br /><applet load="1p6e" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1p6e, resolution 2.3Å" /> | caption="1p6e, resolution 2.3Å" /> | ||
'''STRUCTURE OF THE D55N MUTANT OF PHOSPHOLIPASE C FROM BACILLUS CEREUS IN COMPLEX WITH 1,2-DI-N-PENTANOYL-SN-GLYCERO-3-DITHIOPHOSPHOCHOLINE'''<br /> | '''STRUCTURE OF THE D55N MUTANT OF PHOSPHOLIPASE C FROM BACILLUS CEREUS IN COMPLEX WITH 1,2-DI-N-PENTANOYL-SN-GLYCERO-3-DITHIOPHOSPHOCHOLINE'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Because mutations of the ionizable Asp at position 55 of the | + | Because mutations of the ionizable Asp at position 55 of the phosphatidylcholine preferring phospholipase C from Bacillus cereus (PLC(Bc)) to a non-ionizable Asn generate a mutant enzyme (D55N) with 10(4)-fold lower catalytic activity than the wild-type enzyme, we tentatively identified Asp55 as the general base for the enzymatic reaction. To eliminate the alternate possibility that Asp55 is a structurally important amino acid, the X-ray structures of unbound D55N and complexes of D55N with two non-hydrolyzable substrate analogues have been solved and refined to 2.0, 2.0, and 2.3A, respectively. The structures of unbound wild-type PLC(Bc) and a wild-type PLC(Bc)-complex with a non-hydrolyzable substrate analogue do not change significantly as a result of replacing Asp55 with Asn. These observations demonstrate that Asp55 is not critical for the structural integrity of the enzyme and support the hypothesis that Asp55 is the general base in the PLC(Bc)-catalyzed hydrolysis of phospholipids. |
==About this Structure== | ==About this Structure== | ||
| - | 1P6E is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bacillus_cereus Bacillus cereus] with ZN and PC5 as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Phospholipase_C Phospholipase C], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.1.4.3 3.1.4.3] Full crystallographic information is available from [http:// | + | 1P6E is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bacillus_cereus Bacillus cereus] with <scene name='pdbligand=ZN:'>ZN</scene> and <scene name='pdbligand=PC5:'>PC5</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Phospholipase_C Phospholipase C], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.1.4.3 3.1.4.3] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1P6E OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Phospholipase C]] | [[Category: Phospholipase C]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Antikainen, N | + | [[Category: Antikainen, N M.]] |
| - | [[Category: Franklin, C | + | [[Category: Franklin, C L.]] |
| - | [[Category: Martin, S | + | [[Category: Martin, S F.]] |
| - | [[Category: Monzingo, A | + | [[Category: Monzingo, A F.]] |
| - | [[Category: Robertus, J | + | [[Category: Robertus, J D.]] |
[[Category: PC5]] | [[Category: PC5]] | ||
[[Category: ZN]] | [[Category: ZN]] | ||
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[[Category: tri zn+2 metal core]] | [[Category: tri zn+2 metal core]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:25:38 2008'' |
Revision as of 12:25, 21 February 2008
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STRUCTURE OF THE D55N MUTANT OF PHOSPHOLIPASE C FROM BACILLUS CEREUS IN COMPLEX WITH 1,2-DI-N-PENTANOYL-SN-GLYCERO-3-DITHIOPHOSPHOCHOLINE
Overview
Because mutations of the ionizable Asp at position 55 of the phosphatidylcholine preferring phospholipase C from Bacillus cereus (PLC(Bc)) to a non-ionizable Asn generate a mutant enzyme (D55N) with 10(4)-fold lower catalytic activity than the wild-type enzyme, we tentatively identified Asp55 as the general base for the enzymatic reaction. To eliminate the alternate possibility that Asp55 is a structurally important amino acid, the X-ray structures of unbound D55N and complexes of D55N with two non-hydrolyzable substrate analogues have been solved and refined to 2.0, 2.0, and 2.3A, respectively. The structures of unbound wild-type PLC(Bc) and a wild-type PLC(Bc)-complex with a non-hydrolyzable substrate analogue do not change significantly as a result of replacing Asp55 with Asn. These observations demonstrate that Asp55 is not critical for the structural integrity of the enzyme and support the hypothesis that Asp55 is the general base in the PLC(Bc)-catalyzed hydrolysis of phospholipids.
About this Structure
1P6E is a Single protein structure of sequence from Bacillus cereus with and as ligands. Active as Phospholipase C, with EC number 3.1.4.3 Full crystallographic information is available from OCA.
Reference
Using X-ray crystallography of the Asp55Asn mutant of the phosphatidylcholine-preferring phospholipase C from Bacillus cereus to support the mechanistic role of Asp55 as the general base., Antikainen NM, Monzingo AF, Franklin CL, Robertus JD, Martin SF, Arch Biochem Biophys. 2003 Sep 1;417(1):81-6. PMID:12921783
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