Open AccessTriosephosphate isomerase is a common crystallization contaminant of soluble His‐tagged proteins produced in Escherichia coli
Author(s) -
Kozlov Guennadi,
Vinaik Roohi,
Gehring Kalle
Publication year - 2013
Publication title -
acta crystallographica section f
Language(s) - English
Resource type - Journals
ISSN - 1744-3091
DOI - 10.1107/s1744309113010841
Subject(s) - triosephosphate isomerase , isomerase , escherichia coli , chemistry , crystallization , biochemistry , chromatography , biology , enzyme , organic chemistry , gene
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.