(1) Iron (red circle) enters the chloroplast and is then captured by the conserved cysteine residues in the CR domain of DJA6/5 proteins. (2) During ATP binding, dimerization of SUFC occurs, which induces a large conformational change of the SUFBC2D complex and exposes the buried assembly sites to the SUFB-SUFD surface. (3) This conformational change facilitates the recruitment of the NFS2-SUFE1 complex. Then the sulfur (yellow circle) is extracted from the substrate L-cysteine by the action of NFS2, and further delivered via SUFE1 to SUFB. (4) Iron-loaded DJA6/5 proteins directly interact with SUFE1 and SUFC via their J domain and deliver iron to proposed iron recipient SUFD. (5) Arrival of the electrons allows the building of Fe-S cluster at the SUFB-SUFD interface. After assembly, DJA6/5 protein and NFS2-SUFE1 complex are released and ready for a new cycle. (6-7) The nascent Fe-S cluster (red and yellow circle) is transferred by carrier proteins (NFUs, SUFA, GRXs and HCF101) to client proteins (such as PetC, PsaA/B, PsaC, Fd, PAO). 