[https://www.uniprot.org/uniprot/RS4_ECOLI RS4_ECOLI] One of two assembly initiator proteins for the 30S subunit, it binds directly to 16S rRNA where it nucleates assembly of the body of the 30S subunit.<ref>PMID:2461734</ref> <ref>PMID:11447122</ref> <ref>PMID:15652481</ref> With S5 and S12 plays an important role in translational accuracy; many suppressors of streptomycin-dependent mutants of protein S12 are found in this protein, some but not all of which decrease translational accuracy (ram, ribosomal ambiguity mutations).<ref>PMID:2461734</ref> <ref>PMID:11447122</ref> <ref>PMID:15652481</ref> Plays a role in mRNA unwinding by the ribosome, possibly by forming part of a processivity clamp.<ref>PMID:2461734</ref> <ref>PMID:11447122</ref> <ref>PMID:15652481</ref> Protein S4 is also a translational repressor protein, it controls the translation of the alpha-operon (which codes for S13, S11, S4, RNA polymerase alpha subunit, and L17) by binding to its mRNA.<ref>PMID:2461734</ref> <ref>PMID:11447122</ref> <ref>PMID:15652481</ref> Also functions as a rho-dependent antiterminator of rRNA transcription, increasing the synthesis of rRNA under conditions of excess protein, allowing a more rapid return to homeostasis. Binds directly to RNA polymerase.<ref>PMID:2461734</ref> <ref>PMID:11447122</ref> <ref>PMID:15652481</ref>
8ifb is a 10 chain structure with sequence from Escherichia coli. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
