Required for pre-rRNA processing and maturation of 40S ribosomal subunits. Interacts with RPS19BP1. (Microbial infection) Interacts with Sin nombre virus nucleoprotein (via N-terminus); this interaction probably mediates the loading of the 40S ribosomal subunit on viral capped mRNA during N-mediated translation initiation. Located more specifically in the nucleoli. Higher level expression is seen in the colon carcinoma tissue than normal colon tissue. The disease is caused by variants affecting the gene represented in this entry. Belongs to the eukaryotic ribosomal protein eS19 family.