NADPH-dependent reductase which is a central component of the cytosolic iron-sulfur (Fe-S) protein assembly (CIA) machinery. Transfers electrons from NADPH via its FAD and FMN prosthetic groups to the [2Fe-2S] cluster of CIAPIN1, another key component of the CIA machinery. In turn, this reduced cluster provides electrons for assembly of cytosolic iron-sulfur cluster proteins. It can also reduce the [2Fe-2S] cluster of CISD1 and activate this protein implicated in Fe/S cluster repair (By similarity). In vitro can fully activate methionine synthase/MTR in the presence of soluble cytochrome b5/CYB5A (By similarity). {By
SimilarityUniProtKB:Q9UHB4, Sequence AnalysisHAMAP- Rule:MF_03178}.