Triosephosphate isomerase is a common crystallization contaminant of soluble His-tagged proteins produced in Escherichia coli.

ABSTRACT: Attempts to crystallize several mammalian proteins overexpressed in Escherichia coli revealed a common contaminant, triosephosphate isomerase, a protein involved in glucose metabolism. Even with triosephosphate isomerase present in very small amounts, similarly shaped crystals appeared in the crystallization drops in a number of polyethylene glycol-containing conditions. All of the target proteins were His-tagged and their purification involved immobilized metal-affinity chromatography (IMAC), a step that was likely to lead to triosephosphate isomerase contamination. Analysis of the triosephosphate isomerase crystals led to the structure of E. coli triosephosphate isomerase at 1.85 Å resolution, which is a significant improvement over the previous structure.

SUBMITTER: Kozlov G 

PROVIDER: S-EPMC3660886 | biostudies-literature | 2013 May

REPOSITORIES: biostudies-literature