Ribosomal protein L1. The L1 protein, located near the E-site of the ribosome, forms part of the L1 stalk along with 23S rRNA. In bacteria and archaea, L1 functions both as a ribosomal protein that binds rRNA, and as a translation repressor that binds its own mRNA. Like several other large ribosomal subunit proteins, L1 displays RNA chaperone activity. L1 is one of the largest ribosomal proteins. It is composed of two domains that cycle between open and closed conformations via a hinge motion. The RNA-binding site of L1 is highly conserved, with both mRNA and rRNA binding the same binding site.
Structure:1U63_A: Methanococcus jannaschii L1 forms an interface with mRNA fragments (1U63_B/1U63_D), defined using 3.5 A contacts. - View structure with Cn3D
Structure:1MZP_A: Sulfolobus acidocaldarius L1 forms an interface with 23S rRNA (1MZP_B), defined using 3.5 A contacts. - View structure with Cn3D
Structure:2HGU_C: Thermus thermophilus L1 forms an interface with 23S rRNA (2HGU_A), defined using 3.5 A contacts. - View structure with Cn3D
Comment:L1 has been observed in both open and closed conformations. Because of the hinge motion between the two domains, a slightly different set of residues is within 3.5 A proximity to 23S rRNA in 1MZP and 2HGU.