University of Pennsylvania ScholarlyCommons Publicly Accessible Penn Dissertations 2016 Structure and Function of Metallohydrolases in the Arginase- Deacetylase Family Yang Hai University of Pennsylvania,
[email protected] Follow this and additional works at: https://repository.upenn.edu/edissertations Part of the Biochemistry Commons Recommended Citation Hai, Yang, "Structure and Function of Metallohydrolases in the Arginase-Deacetylase Family" (2016). Publicly Accessible Penn Dissertations. 1753. https://repository.upenn.edu/edissertations/1753 This paper is posted at ScholarlyCommons. https://repository.upenn.edu/edissertations/1753 For more information, please contact
[email protected]. Structure and Function of Metallohydrolases in the Arginase-Deacetylase Family Abstract Arginases and deacetylases are metallohydrolases that catalyze two distinct chemical transformations. The arginases catalyze the hydrolysis of the guanidinium group of arginine by using a hydroxide ion 2+ 2+ bridging the binuclear manganese cluster (Mn A-Mn B) for nucleophilic attack. The deacetylases catalyze the hydrolysis of amide bonds by using a mononuclear Zn2+-ion activated water molecule as the nucleophile. Despite the diverse functions, metallohydrolases of the arginase-deacetylase superfamily 2+ share the same characteristic α/β hydrolase core fold and a conserved metal binding site (the Mn B site in arginase corresponds to the catalytic Zn2+ site in deacetylase) which is essential for catalysis in both enzymes. We report crystal structure of formiminoglutamase from the parasitic protozoan Trypanosoma cruzi and confirm that formiminoglutamase is a Mn2+-requiring hydrolase that belongs to the arginase- deacetylase superfamily. We also report the crystal structure of an arginase-like protein from Trypanosoma brucei (TbARG) with unknown function. Although its biological role remains enigmatic, the 2+ evolutionarily more conserved Mn B site can be readily restored in TbARG through side-directed mutagenesis.