[Show abstract][Hide abstract] ABSTRACT: The structure of a putative Raf kinase inhibitor protein (RKIP) homolog from the eukaryotic parasite Plasmodium vivax has been studied to a resolution of 1.3 A using multiple-wavelength anomalous diffraction at the Se K edge. This protozoan protein is topologically similar to previously studied members of the phosphatidylethanolamine-binding protein (PEBP) sequence family, but exhibits a distinctive left-handed alpha-helical region at one side of the canonical phospholipid-binding site. Re-examination of previously determined PEBP structures suggests that the P. vivax protein and yeast carboxypeptidase Y inhibitor may represent a structurally distinct subfamily of the diverse PEBP-sequence family.
Preview · Article · Apr 2007 · Acta Crystallographica Section F Structural Biology and Crystallization Communications
[Show abstract][Hide abstract] ABSTRACT: The gene product of structural genomics target Lmaj006129 from Leishmania major codes for a 164-residue protein of unknown function. When SeMet expression of the full-length gene product failed, several truncation variants were created with the aid of Ginzu, a domain-prediction method. 11 truncations were selected for expression, purification and crystallization based upon secondary-structure elements and disorder. The structure of one of these variants, Lmaj006129AAH, was solved by multiple-wavelength anomalous diffraction (MAD) using ELVES, an automatic protein crystal structure-determination system. This model was then successfully used as a molecular-replacement probe for the parent full-length target, Lmaj006129AAA. The final structure of Lmaj006129AAA was refined to an R value of 0.185 (Rfree = 0.229) at 1.60 A resolution. Structure and sequence comparisons based on Lmaj006129AAA suggest that proteins belonging to Pfam sequence families PF04543 and PF01878 may share a common ligand-binding motif.
Full-text · Article · Apr 2006 · Acta Crystallographica Section F Structural Biology and Crystallization Communications