Figure 6.

The Cys⁷⁷⁹, Cys⁷⁸⁷, and Cys⁷⁹⁰ of RRM1 and Cys³² and Cys³⁵ of hTrx1 played vital roles during RRM1 enzymatic activity regeneration and RRM1-hTrx1 interaction. A, sequence alignment of the C-terminal regions of the RR large subunits from different species. B, RRM1 (wild type or C-terminal cysteine mutants) specific activities with different reductants as indicated in supplemental Table S1 (50 mm DTT, 25 μm hTrx1, or 25 μm hGrx1). C, GST pulldown assay was performed by incubating purified RRM1-His (wild type or C-terminal cysteine mutants) proteins with GST-hTrx1 immobilized on GST resin and analyzed by immunoblotting. D, schematic diagram of human thioredoxin1. E, GST pulldown assay was performed by incubating purified RRM1-His (wild-type) protein with GST-hTrx1 (wild type or mutants) immobilized on GST resin and analyzed by immunoblotting. The data shown represent the mean ± S.D. (n = 3). *, p < 0.01. Error bars represent S.D. yGR, yeast glutathione reductase.