May be a ribosome silencing factor (Potential). Involved in plastid biogenesis. Plastids affected by a mutation in Iojap lose the ability to perform translation and lack plastid ribosomes. Interacts with chloroplast ribosomal protein L14 (rpl14). Plastids lose the ability to perform translation and lack plastid ribosomes. Belongs to the Iojap/RsfS family.