Acidophilic adaptations in the structure of Acetobacter aceti N5-carboxyaminoimidazole ribonucleotide mutase (PurE).
Settembre, E.C., Chittuluru, J.R., Mill, C.P., Kappock, T.J., Ealick, S.E.(2004) Acta Crystallogr D Biol Crystallogr 60: 1753-1760
- PubMed: 15388921 
- DOI: https://doi.org/10.1107/S090744490401858X
- Primary Citation of Related Structures:  
1U11 - PubMed Abstract: 
The crystal structure of Acetobacter aceti PurE was determined to a resolution of 1.55 A and is compared with the known structures of the class I PurEs from a mesophile, Escherichia coli, and a thermophile, Thermotoga maritima. Analyses of the general factors that increase protein stability are examined as potential explanations for the acid stability of A. aceti PurE. Increased inter-subunit hydrogen bonding and an increased number of arginine-containing salt bridges appear to account for the bulk of the increased acid stability. A chain of histidines linking two active sites is discussed in the context of the proton transfers catalyzed by the enzyme.
Organizational Affiliation: 
Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY 14853, USA.