Part of the ribosome quality control system (RQC). Recruits Ala-charged tRNA and directs the elongation of stalled nascent chains on 50S ribosomal subunits, leading to non-templated C-terminal Ala extensions (Ala tail). The Ala tail promotes nascent chain degradation. May add between 1 and at least 8 Ala residues. Binds to stalled 50S ribosomal subunits. Associates with stalled 50S ribosomal subunits (By similarity). Recombinant protein interacts with the N-terminal 30 kDa of human fibronectin (FN1) (PubMed:27834729). The N-terminus (residues 1-268) and C-terminus (271-552) form 2 separate domains; the N-terminus is globular while the C-terminus is elongated. The N-terminus binds to S.suis cells while the C-terminus binds to human HEp-2 cells. Incubation with the C-terminus stimulates ERK and p38 phosphorylation in HEp-2 cells. About 25% decreased adherence to human HEp-2 cells, about 50% decrease in binding to immobilized fibronectin. HEp-2 cells treated with mutant bacteria secrete less IL-6 and IL-8, activate ERK and p38 more slowly and to a lesser extent than with wild-type bacteria. Repeated attempts to crystallize a full-length protein yields proteins cleaved between the N- and C-terminal domains. Belongs to the NEMF family.