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| {{STRUCTURE_1oxw| PDB=1oxw | SCENE= }} | | {{STRUCTURE_1oxw| PDB=1oxw | SCENE= }} |
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| '''The Crystal Structure of SeMet Patatin'''
| | ===The Crystal Structure of SeMet Patatin=== |
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| ==Overview==
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| Patatin is a nonspecific lipid acyl hydrolase that accounts for approximately 40% of the total soluble protein in mature potato tubers, and it has potent insecticidal activity against the corn rootworm. We determined the X-ray crystal structure of a His-tagged variant of an isozyme of patatin, Pat17, to 2.2 A resolution, employing SeMet multiwavelength anomalous dispersion (MAD) phasing methods. The patatin crystal structure has three molecules in the asymmetric unit, an R-factor of 22.0%, and an R(free) of 27.2% (for 10% of the data not included in the refinement) and includes 498 water molecules. The structure notably revealed that patatin has a Ser-Asp catalytic dyad and an active site like that of human cytosolic phospholipase A(2) (cPLA(2)) [Dessen, A., et al. (1999) Cell 97, 349-360]. In addition, patatin has a folding topology related to that of the catalytic domain of cPLA(2) and unlike the canonical alpha/beta-hydrolase fold. The structure confirms our site-directed mutagenesis and bioactivity data that initially suggested patatin possessed a Ser-Asp catalytic dyad. Alanine-scanning mutagenesis revealed that Ser77 and Asp215 were critical for both esterase and bioactivity, consistent with prior work implicating a Ser residue [Strickland, J. H., et al. (1995) Plant Physiol. 109, 667-674] and a Ser-Asp dyad [Hirschberg, H. J. H. B., et al. (2001) Eur. J. Biochem. 268, 5037-5044] in patatin's catalytic activity. The crystal structure aids the understanding of other structure-function relationships in patatin. Patatin does not display interfacial activation, a hallmark feature of lipases, and this is likely due to the fact that it lacks a flexible lid that can shield the active site.
| | The line below this paragraph, {{ABSTRACT_PUBMED_12779324}}, adds the Publication Abstract to the page |
| | (as it appears on PubMed at http://www.pubmed.gov), where 12779324 is the PubMed ID number. |
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| | {{ABSTRACT_PUBMED_12779324}} |
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| ==About this Structure== | | ==About this Structure== |
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| [[Category: Alpha/beta class fold with approximately three layer]] | | [[Category: Alpha/beta class fold with approximately three layer]] |
| [[Category: Alpha/beta/alpha in content. possesses a central six-stranded beta sheet with alpha-helices front & back]] | | [[Category: Alpha/beta/alpha in content. possesses a central six-stranded beta sheet with alpha-helices front & back]] |
| ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sat May 3 04:24:50 2008'' | | |
| | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Tue Jul 29 09:19:27 2008'' |
