Involved in the binding of tRNA to the ribosomes (PubMed:6759118). Part of the processive rRNA transcription and antitermination complex (rrnTAC). The complex forms an RNA-chaperone ring around the RNA exit tunnel of RNA polymerase (RNAP). It supports rapid transcription and antitermination of rRNA operons, cotranscriptional rRNA folding, and annealing of distal rRNA regions to allow correct ribosome biogenesis (PubMed:32871103). In complex with NusB is involved in the regulation of ribosomal RNA (rRNA) biosynthesis by transcriptional antitermination. S10 binds RNA non-specifically and increases the affinity of NusB for the boxA RNA sequence (PubMed:7678781, PubMed:11884128, PubMed:16109710). S10 may constitute the critical antitermination component of the NusB-S10 complex (PubMed:19111659). Part of the 30S ribosomal subunit (PubMed:10094780, PubMed:12244297, PubMed:12809609, PubMed:16272117, PubMed:27906160, PubMed:27906161, PubMed:27934701, PubMed:28077875, PubMed:7007073). Can also form a heterodimer with the transcription antitermination protein NusB (PubMed:1731086, PubMed:11884128, PubMed:16109710, PubMed:19111659). Binding of S10 to NusB is mutually exclusive with its incorporation into the ribosome (PubMed:19111659). The rRNA transcription and antitermination complex (rrnTAC) consists of RNAP, NusA, NusB, NusE (this protein), NusG, SubB, ribosomal protein S4, DNA and precursor rRNA; S4 is more flexible than other subunits (PubMed:32871103). Belongs to the universal ribosomal protein uS10 family.