Spurred by the recent proposal of a histidyl radical 41 (3) as the first intermediate in a protective hole-hopping pathway, we investigated whether the histidyl radical (3) can abstract a hydrogen from the tyrosine, thereby restoring histidine while forming a tyrosyl radical (2). This reaction is labeled III in Fig. . The reaction barrier and energies are shown in Fig. and Fig. . Interestingly, the two LPMOs are remarkably different: for TaAA9 the reaction is kinetically feasible with a barrier of 75 kJ/mol (59 kJ/mol for TPSS), and is predicted to be thermodynamically favorable with a reaction energy of -129 kJ/mol for both functionals.