The function of LTO1 (LTO1 maturation factor of ABCE1, ENSG00000149716) is as follows. The complex LTO1:YAE1 functions as a target specific adapter that probably recruits apo-ABCE1 to the cytosolic iron-sulfur protein assembly (CIA) complex machinery (PubMed:26182403). May be required for biogenesis of the large ribosomal subunit and initiation of translation (PubMed:23318452). May play a role in the regulation of proline metabolism and ROS production (PubMed:24930674). {ECO:0000269|PubMed:23318452, ECO:0000269|PubMed:24930674, ECO:0000269|PubMed:26182403}.