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1oxw
From Proteopedia
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The Crystal Structure of SeMet Patatin
Overview
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.
About this Structure
1OXW is a Single protein structure of sequence from Solanum cardiophyllum. Full crystallographic information is available from OCA.
Reference
The crystal structure, mutagenesis, and activity studies reveal that patatin is a lipid acyl hydrolase with a Ser-Asp catalytic dyad., Rydel TJ, Williams JM, Krieger E, Moshiri F, Stallings WC, Brown SM, Pershing JC, Purcell JP, Alibhai MF, Biochemistry. 2003 Jun 10;42(22):6696-708. PMID:12779324
Page seeded by OCA on Tue Nov 20 23:17:02 2007
Categories: Single protein | Solanum cardiophyllum | Alibhai, M.F. | Brown, S.M. | Krieger, E. | Moshiri, F. | Pershing, J.C. | Purcell, J.P. | Rydel, T.J. | Stallings, W.C. | Williams, J.M. | Alpha/beta class fold with approximately three layers | Alpha/beta/alpha in content. possesses a central six-stranded beta sheet with alpha-helices front & back
