Download MendeleyDetermination of a protein structure by iodination: the structure of iodinated acetylxylan esterase.
Ghosh, D., Erman, M., Sawicki, M., Lala, P., Weeks, D.R., Li, N., Pangborn, W., Thiel, D.J., Jornvall, H., Gutierrez, R., Eyzaguirre, J.(1999) Acta Crystallogr D Biol Crystallogr 55: 779-784
- PubMed: 10089308
- DOI: https://doi.org/10.1107/s0907444999000244
- Primary Citation of Related Structures:
1BS9, 2AXE - PubMed Abstract:
Enzymatic and non-enzymatic iodination of the amino acid tyrosine is a well known phenomenon. The iodination technique has been widely used for labeling proteins. Using high-resolution X-ray crystallographic techniques, the chemical and three-dimensional structures of iodotyrosines formed by non-enzymatic incorporation of I atoms into tyrosine residues of a crystalline protein are described. Acetylxylan esterase (AXE II; 207 amino-acid residues) from Penicillium purpurogenum has substrate specificities towards acetate esters of D-xylopyranose residues in xylan and belongs to a new class of alpha/beta hydrolases. The crystals of the enzyme are highly ordered, tightly packed and diffract to better than sub-angström resolution at 85 K. The iodination technique has been utilized to prepare an isomorphous derivative of the AXE II crystal. The structure of the enzyme determined at 1.10 A resolution exclusively by normal and anomalous scattering from I atoms, along with the structure of the iodinated complex at 1.80 A resolution, demonstrate the formation of covalent bonds between I atoms and C atoms at ortho positions to the hydroxyl groups of two tyrosyl moieties, yielding iodotyrosines.
Organizational Affiliation:
Hauptman-Woodward Medical Research Institute, 73 High Street, Buffalo, New York 14203, USA. ghosh@hwi.buffalo.edu
