Ribosome assembly is a complex process involving the coordination of multiple enzymes. A recently discovered endoribonuclease (RNase), Las1, and the poly-nucleotide kinase (PNK), Grc3, assemble into a complex. To attempt to understand the coordination of the two enzymes in this complex, we performed chemical crosslinking and mass spectrometry and also solved a series of cryo-electron microscopy structures of RNase PNK in multiple conformational states.