... connected by a yellow line. (B)Vicinity of aTyr114 of the Co-type NHase.The wild-type, aY114T mutant, and Fe-typeNHase are shown in yellow, purple, and cyan,respectively. The hydrogen bonds ... of the Co-type NHase.Thewild-typeenzyme,aT109S mutant, and Fe-type NHase are shown in yellow, red and cyan, respectively. The Cc2atomofaThr109 and the Cc1atomofaVal136 of the Co-typeNHase are ... 2-cyano-2-propyl hydroperoxide irreversibly inac-tivates the enzyme, probably by the oxidation of aCys-SOHto aCys-SO2H [29]. Carboxylic oxygen atoms of both typeswere directly coordinated...