The Noc proteins involved in ribosome synthesis and export contain divergent HEAT repeats

Abstract

The Noc1–4p proteins were previously reported to be involved in intranuclear and nucleocytoplasmic transport of pre-ribosomes. Using fold recognition and structural modeling, we show that Noc1–4p are largely comprised of α-helical repeats similar to HEAT repeats. Because other HEAT-repeat proteins play key roles in transport processes, this finding provides a plausible mechanistic explanation for the function of the Noc proteins.