Creation of a putative third metal binding site in type II dihydroorotases significantly enhances enzyme activity

Title:Creation of a putative third metal binding site in type II dihydroorotases significantly enhances enzyme activity

Volume: 22 Issue: 12

Author(s): Yen-Hua Huang and Cheng-Yang Huang

Affiliation:

Keywords: CAD, dihydroorotase, metalloenzyme, amidohydrolase, metal content.

Abstract: Dihydroorotase (DHOase) is the third enzyme in the de novo biosynthesis pathway of pyrimidine nucleotides. DHOase is divided into two types (I and II). Type II DHOase generally contains a binuclear metal center in its active site. Recently, the crystal structure of DHOase domain in human CAD protein (huDHOase) has revealed three metal ions in the protein’s active site. However, whether type II DHOase can have the critical third metal ion, as observed in huDHOase, remains unknown. In the present study, the putative third metal binding site in type II enzymes, such as the prokaryotic Salmonella enterica serovar Typhimurium LT2 DHOase (StDHOase) and the eukaryotic Saccharomyces cerevisiae DHOase (ScDHOase), was created and identified. StDHOase T198E and ScDHOase T208E mutants had higher activities compared with their wild-type enzymes. The need for a higher DHOase stability and activity may drive creation of the third metal ion binding site in huDHOase, which can be achieved by mutating a highly conserved position T in type II dihydroorotases to E, similar to that in huDHOase.

Cite this article as:

Huang Yen-Hua and Huang Cheng-Yang, Creation of a putative third metal binding site in type II dihydroorotases significantly enhances enzyme activity, Protein & Peptide Letters 2015; 22 (12) . https://dx.doi.org/10.2174/0929866522666151008151145

DOI https://dx.doi.org/10.2174/0929866522666151008151145	Print ISSN 0929-8665
Publisher Name Bentham Science Publisher	Online ISSN 1875-5305