1it5
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(New page: 200px<br /><applet load="1it5" size="450" color="white" frame="true" align="right" spinBox="true" caption="1it5" /> '''Solution structure of apo-type PLA2 from Str...)
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Revision as of 20:23, 24 November 2007
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Solution structure of apo-type PLA2 from Streptomyces violaceruber A-2688.
Overview
Until now, phospholipase A(2) (PLA(2); EC 3.1.14) has been found only from, eukaryotic sources. In the present study, we found a secreted PLA(2), which is produced by a soil bacterium, Streptomyces violaceoruber A-2688, demonstrating that the enzyme is the first phospholipase A(2) identified, in prokaryote. After characterization of the novel PLA(2), a gene encoding, the enzyme was cloned, sequenced, and overexpressed using a Streptomyces, host-vector system. The amino acid sequence showed that the prokaryotic, PLA(2) has only four cysteines and less homology to the eukaryotic ones, which have 12-16 cysteines. The solution structures of the prokaryotic, PLA(2), bound and unbound with calcium(II) ion, were determined by using, the NMR technique and structure calculation. The overall structure of the, S. violaceoruber PLA(2), which is composed of only five alpha-helices, is, completely different from those of eukaryotic PLA(2)s, which consist of, beta-sheets and alpha-helices. The structure of the calcium-binding domain, is obviously distinct from that without the ion; the ligands for the, calcium(II) ion are the two carboxylates of Asp(43) (monodentate) and, Asp(65) (bidentate), the carbonyl oxygen of Leu(44), and three water, molecules. A calcium-binding experiment showed that the calcium, dissociation constant ( approximately 5 mm) for the prokaryotic PLA(2) is, much larger than those of eukaryotic ones.
About this Structure
1IT5 is a Single protein structure of sequence from Streptomyces violaceoruber. Active as Phospholipase A(2), with EC number 3.1.1.4 Full crystallographic information is available from OCA.
Reference
A novel prokaryotic phospholipase A2. Characterization, gene cloning, and solution structure., Sugiyama M, Ohtani K, Izuhara M, Koike T, Suzuki K, Imamura S, Misaki H, J Biol Chem. 2002 May 31;277(22):20051-8. Epub 2002 Mar 15. PMID:11897786
Page seeded by OCA on Sat Nov 24 22:30:44 2007
