This superfamily entry includes the ribosomal protein S7 found in the small subunit (30S) of the ribosome (in eukaryotes, this ribosomal protein is known as S5). Although S7 has been more extensively studied than its eukaryotic homologue S5, the high degree of sequence similarity of S5 and S7 suggests conservation of function(s) of this ribosomal protein PMID:8524651. It is located in the 'head' of the 30S subunit close to proteins S9, S13, S14 and S19. The representative domain consists of a bundle of six helices and an extended beta hairpin between helices 3 and 4, with two or more RNA-binding sites on its surface.

S7 is a primary RNA-binding ribosomal protein which recognises and binds a defined region of 16S RNA in the absence of other ribosomal proteins. Additionally, it has a key-role in initiating the assembly of the 30S ribosomal subunit. It is required for proper folding of a large 3' domain of 16S ribosomal RNA. S7 controls the synthesis of ribosomal proteins by a feedback mechanism at the level of translation. Also, S7 regulates its own synthesis by binding to its own mRNA. This ability of S7 to bind both messenger and ribosomal RNAs makes determination of its mode of RNA recognition particularly interesting.

INTERPRO:IPR036823, PFAM:PF00177,PMID:9331418,PMID:11686933