Essential component of the cytosolic iron-sulfur (Fe-S) protein assembly (CIA) machinery (PubMed:23104832). Required for the maturation of extramitochondrial Fe/S proteins (By similarity). Required for expression of the imprinted FWA gene, for seed development and is involved in the oxidative stress response in vegetative tissues (PubMed:23734982). Involved in the regulation of cell size, ploidy and cell cycle progression (PubMed:23639116). Required for growth under normoxic conditions and necessary for recovery after hypoxic treatment but its action is reactive oxygen species (ROS) independent (PubMed:23639116). Part of a complex composed of AE7, CIA1, MMS19 and NAR1. Interacts with CIA1. Expressed in developing tissues, including shoot apex, young leaves, vascular tissues, root tips, pedicels, carpels and developing seeds. Expressed throughout plant development. Embryonic lethality when homozygous (PubMed:23104832, PubMed:23734982, PubMed:23639116). Coordinates probably two (Fe-S) clusters with different magnetic properties (PubMed:18329103). Knockdown mutants have a dwarf phenotype, but are indistinguishable from wild type under hypoxic conditions (PubMed:18329103, PubMed:23639116). Belongs to the NARF family. Truncated N-terminus. The predicted gene At4g16440 has been split into 3 genes: At4g16440, At4g16442 and At4g16444. The predicted gene At4g16440 has been split into 3 genes: At4g16440, At4g16442 and At4g16444.