1za0
From Proteopedia
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X-ray structure of putative acyl-ACP desaturase DesA2 from Mycobacterium tuberculosis H37Rv
Overview
Genome sequencing showed that two proteins in Mycobacterium tuberculosis, H37Rv contain the metal binding motif (D/E)X(2)HX(approximately, 100)(D/E)X(2)H characteristic of the soluble diiron enzyme superfamily., These putative acyl-ACP desaturase genes desA1 and desA2 were cloned from, genomic DNA and expressed in Escherichia coli BL21(DE3). DesA1 was found, to be insoluble, but in contrast, DesA2 was a soluble protein amenable to, biophysical characterization. Here, we report the 2.0 A resolution X-ray, structure of DesA2 determined by multiple anomalous dispersion (MAD), phasing from a Se-met derivative and refinement against diffraction data, obtained on the native protein. The X-ray structure shows that DesA2 is a, homodimeric protein with a four-helix bundle core flanked by five, additional helices that overlay with 192 structurally equivalent amino, acids in the structure of stearoyl-ACP Delta9 desaturase from castor plant, with an rms difference 1.42 A. In the DesA2 crystals, one metal (likely Mn, from the crystallization buffer) was bound in high occupancy at the B-site, of the conserved metal binding motif, while the A-site was not occupied by, a metal ion. Instead, the amino group of Lys-76 occupied this position., The relationships between DesA2 and known diiron enzymes are discussed.
About this Structure
1ZA0 is a Single protein structure of sequence from Mycobacterium tuberculosis with MN and EDO as ligands. Active as [acyl-carrier-protein_desaturase Acyl-[acyl-carrier-protein] desaturase], with EC number 1.14.19.2 Full crystallographic information is available from OCA.
Reference
X-ray structure of putative acyl-ACP desaturase DesA2 from Mycobacterium tuberculosis H37Rv., Dyer DH, Lyle KS, Rayment I, Fox BG, Protein Sci. 2005 Jun;14(6):1508-17. PMID:15929999 [[Category: Acyl-[acyl-carrier-protein] desaturase]]
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