A proposed reaction mechanism for rice NADPH thioredoxin reductase C, an enzyme with protein disulfide reductase activity

Pérez-Ruiz, Juan Manuel; Cejudo, Francisco Javier

doi:10.1016/j.febslet.2009.03.067

« Previous Next »FEBS Letters
Volume 583, Issue 9 , Pages 1399-1402, 6 May 2009

A proposed reaction mechanism for rice NADPH thioredoxin reductase C, an enzyme with protein disulfide reductase activity

Edited by Judit Ovádi

Instituto de Bioquímica Vegetal y Fotosíntesis, Universidad de Sevilla and CSIC, Avda Américo Vespucio 49, 41092 Sevilla, Spain

Received 4 March 2009; received in revised form 26 March 2009; accepted 27 March 2009. published online 03 April 2009.

Abstract

NADPH thioredoxin reductase C (NTRC) is an interesting NTR with a thioredoxin (Trx) domain at the C-terminus, able to conjugate both activities for 2-Cys peroxiredoxin (Prx) reduction. NTRC is dimeric in the presence of NADPH and interacted with dimeric 2-Cys Prx through the Trx module by a mixed disulfide between Cys377 of NTRC and Cys61 of the 2-Cys Prx. NTRC variants of both NTR and Trx active sites were inactive, but 1:1 mixtures of both variants allowed partial recovery of activity suggesting inter-subunit transfer of electrons during catalysis. Based on these results we propose a model for the reaction mechanism of NTRC.