4bpm
From Proteopedia
Crystal structure of a human integral membrane enzyme
Structural highlights
DiseaseLTC4S_HUMAN Defects in LTC4S are the cause of leukotriene C4 synthase deficiency (LTC4 synthase deficiency) [MIM:246530. LTC4 synthase deficiency is a fatal neurometabolic developmental disorder. It is associated with muscular hypotonia, psychomotor retardation, failure to thrive, and microcephaly. FunctionLTC4S_HUMAN Catalyzes the conjugation of leukotriene A4 with reduced glutathione to form leukotriene C4.PTGES_HUMAN Catalyzes the oxidoreduction of prostaglandin endoperoxide H2 (PGH2) to prostaglandin E2 (PGE2).[1] Publication Abstract from PubMedThe lipidic mesophase or in meso method for crystallizing membrane proteins has several high profile targets to its credit and is growing in popularity. Despite its success, the method is in its infancy as far as rational crystallogenesis is concerned. Consequently, significant time, effort, and resources are still required to generate structure-grade crystals, especially with a new target type. Therefore, a need exists for crystallogenesis protocols that are effective with a broad range of membrane protein types. Recently, a strategy for crystallizing a prokaryotic alpha-helical membrane protein, diacylglycerol kinase (DgkA), by the in meso method was reported (Cryst. Growth. Des.2013, 14, 2846-2857). Here, we describe its application to the human alpha-helical microsomal prostaglandin E2 synthase 1 (mPGES1). While the DgkA strategy proved useful, significant modifications were needed to generate structure-quality crystals of this important therapeutic target. These included protein engineering, using an additive phospholipid in the hosting mesophase, performing multiple rounds of salt screening, and carrying out trials at 4 degrees C in the presence of a tight binding ligand. The crystallization strategy detailed here should prove useful for generating structures of other integral membrane proteins by the in meso method. Crystallizing Membrane Proteins in the Lipidic Mesophase. Experience with Human Prostaglandin E2 Synthase 1 and an Evolving Strategy.,Li D, Howe N, Dukkipati A, Shah ST, Bax BD, Edge C, Bridges A, Hardwicke P, Singh OM, Giblin G, Pautsch A, Pfau R, Schnapp G, Wang M, Olieric V, Caffrey M Cryst Growth Des. 2014 Apr 2;14(4):2034-2047. Epub 2014 Mar 7. PMID:24803849[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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