4v42

Structural highlights

Function

[RL7_THEMA] Seems to be the binding site for several of the factors involved in protein synthesis and appears to be essential for accurate translation. [RL6_GEOSE] It is located near the subunit interface in the base of the L7/L12 stalk, and near the tRNA binding site of the peptidyltransferase center (By similarity). This protein binds to the 23S rRNA, and is important in its secondary structure.[HAMAP-Rule:MF_01365] [RS4_THET8] One of the primary rRNA binding proteins, it binds directly to 16S rRNA where it helps nucleate assembly of the body and platform of the 30S subunit. Binds mRNA in the 70S ribosome, positioning it for translation.[HAMAP-Rule:MF_01306_B] [RS14Z_THET8] Required for the assembly of 30S particles and may also be responsible for determining the conformation of the 16S rRNA at the A site (By similarity). Binds 16S rRNA in center of the 30S subunit head.[HAMAP-Rule:MF_01364_B] [RS15_THET8] One of the primary rRNA binding proteins, it binds directly to 16S rRNA where it helps nucleate assembly of the platform of the 30S subunit by binding and bridging several RNA helices of the 16S rRNA (By similarity).[HAMAP-Rule:MF_01343] Forms an intersubunit bridge (bridge B4) with the 23S rRNA of the 50S subunit in the ribosome.[HAMAP-Rule:MF_01343] [RL4_HALMA] One of the primary rRNA binding proteins, this protein initially binds near the 5'-end of the 23S rRNA. It is important during the early stages of 50S assembly (By similarity).[HAMAP-Rule:MF_01328_A] Makes multiple contacts with different domains of the 23S rRNA in the assembled 50S subunit.[HAMAP-Rule:MF_01328_A] Forms part of the polypeptide exit tunnel, in which it helps forms a bend with protein L22. Contacts the macrolide antibiotic spiramycin in the polypeptide exit tunnel.[HAMAP-Rule:MF_01328_A] [RS13_THET8] Located at the top of the head of the 30S subunit, it contacts several helices of the 16S rRNA. In the 70S ribosome structure it contacts the 23S rRNA (bridge B1a) and protein L5 of the 50S subunit (bridge B1b), connecting the top of the two subunits; these bridges are in contact with the A site and P site tRNAs respectively and are implicated in movement during ribosome translocation. Separately contacts the tRNAs in the A and P sites.[HAMAP-Rule:MF_01315] [RL24_HALMA] One of two assembly initiator proteins, it binds directly to the 5'-end of the 23S rRNA, where it nucleates assembly of the 50S subunit (By similarity).[HAMAP-Rule:MF_01326_A] Stabilizes the tertiary rRNA structure within the 23S rRNA domain (domain I) to which it binds. Located at the polypeptide exit tunnel on the outside of the subunit.[HAMAP-Rule:MF_01326_A] [RL1_THETH] The L1 stalk is quite mobile in the ribosome, and is involved in E site tRNA release (By similarity). Binds directly to 23S rRNA.[HAMAP-Rule:MF_01318] Protein L1 is also a translational repressor protein, it controls the translation of the L11 operon by binding to its mRNA (By similarity).[HAMAP-Rule:MF_01318] [RL2_GEOSE] One of the primary rRNA binding proteins. Required for association of the 30S and 50S subunits to form the 70S ribosome, for tRNA binding and peptide bond formation. It has been suggested to have peptidyltransferase activity; this is somewhat controversial. Makes several contacts with the 16S rRNA in the 70S ribosome (By similarity).[HAMAP-Rule:MF_01320] [RL18_HALMA] This is one of 5 proteins that mediate the attachment of the 5S rRNA onto the large ribosomal subunit, where it forms part of the central protuberance and stabilizes the orientation of adjacent RNA domains.[HAMAP-Rule:MF_01337_A] [RS11_THET8] Located on the upper part of the platform of the 30S subunit, where it bridges several disparate RNA helices of the 16S rRNA. Forms part of the Shine-Dalgarno cleft in the 70S ribosome, where it interacts both with the Shine-Dalgarno helix and mRNA.[HAMAP-Rule:MF_01310] [RSHX_THETH] Binds at the top of the head of the 30S subunit. It stabilizes a number of different RNA elements and thus is important for subunit structure (By similarity). [RS7_THET8] One of the primary rRNA binding proteins, it binds directly to 3'-end of the 16S rRNA where it nucleates assembly of the head domain of the 30S subunit. Is located at the subunit interface close to the decoding center. Binds mRNA and the E site tRNA blocking its exit path in the ribosome. This blockage implies that this section of the ribosome must be able to move to release the deacetylated tRNA.[HAMAP-Rule:MF_00480_B] [RL5_HALMA] This is 1 of 5 proteins that mediates the attachment of the 5S rRNA onto the large ribosomal subunit, stabilizing the orientation of adjacent RNA domains. Forms part of the central protuberance. Modeling places the A and P site tRNAs in close proximity to this protein; the 5S rRNA and some of its associated proteins might help stabilize positioning of ribosome-bound tRNAs. In the 70S ribosome it is thought to contact protein S13 of the 30S subunit (bridge B1b), connecting the 2 subunits; this bridge is implicated in subunit movement.[HAMAP-Rule:MF_01333_A] [RL11_THEMA] This protein binds directly to 23S ribosomal RNA. [RS8_THET8] One of the primary rRNA binding proteins, it binds directly to 16S rRNA where it helps nucleate assembly of the platform of the 30S subunit central domain. The combined cluster of proteins S8, S12 and S17 appears to hold together the shoulder and platform of the 30S subunit.[HAMAP-Rule:MF_01302_B] [RL22_THETH] This protein binds specifically to 23S rRNA; its binding is stimulated by other ribosomal proteins, e.g. L4, L17, and L20. It is important during the early stages of 50S assembly. It makes multiple contacts with different domains of the 23S rRNA in the assembled 50S subunit and ribosome (By similarity). The globular domain of the protein is one of the proteins that surrounds the polypeptide exit tunnel on the outside of the subunit, while an extended beta-hairpin is found that penetrates into the center of the 70S ribosome. This extension seems to form part of the wall of the exit tunnel (By similarity). Deleting residues 82 to 84 (the equivalent deletion in E.coli renders cells resistant to erythromycin) would probably cause the tip of the hairpin to penetrate into the tunnel. [RS19_THETH] Protein S19 forms a complex with S13 that binds strongly to the 16S ribosomal RNA (By similarity). [RL29_HALMA] Stabilizes the tertiary rRNA structure within the 23S rRNA domain (domain I) to which it binds. Located at the polypeptide exit tunnel on the outside of the subunit.[HAMAP-Rule:MF_00374] [RS10_THET8] Part of the top of the 30S subunit head.[HAMAP-Rule:MF_00508] [RL3_HALMA] One of the primary rRNA binding proteins, it binds directly near the 3'-end of the 23S rRNA, where it nucleates assembly of the 50S subunit (By similarity).[HAMAP-Rule:MF_01325_A] [RS3_THET2] Binds the lower part of the 30S subunit head. Binds mRNA in the 70S ribosome, positioning it for translation (By similarity). [RL13_HALMA] This protein is one of the early assembly proteins of the 50S ribosomal subunit (By similarity). Binds to 23S rRNA.[HAMAP-Rule:MF_01366] [RS6_THET8] Located on the outer edge of the platform on the body of the 30S subunit.[HAMAP-Rule:MF_00360] [RL24E_HALMA] Binds to the 23S rRNA.[HAMAP-Rule:MF_00773] [RS9_THET8] Part of the top of the head of the 30S subunit. The C-terminal region penetrates the head emerging in the P-site where it contacts tRNA.[HAMAP-Rule:MF_00532_B] [RS12_THET8] With S4 and S5 plays an important role in translational accuracy (By similarity).[HAMAP-Rule:MF_00403_B] Interacts with and stabilizes bases of the 16S rRNA that are involved in tRNA selection in the A site and with the mRNA backbone. Located at the interface of the 30S and 50S subunits, it traverses the body of the 30S subunit contacting proteins on the other side and probably holding the rRNA structure together. The combined cluster of proteins S8, S12 and S17 appears to hold together the shoulder and platform of the 30S subunit.[HAMAP-Rule:MF_00403_B] [RL15_HALMA] Binds to the 23S rRNA.[HAMAP-Rule:MF_01341_A] [RS5_THET8] With S4 and S12 plays an important role in translational accuracy (By similarity).[HAMAP-Rule:MF_01307_B] Located at the back of the 30S subunit body where it stabilizes the conformation of the head with respect to the body. Binds mRNA in the 70S ribosome, positioning it for translation.[HAMAP-Rule:MF_01307_B] [RL9_GEOSE] Binds to the 23S rRNA. [RL25_ECOLI] This is one of the proteins that binds to the 5S RNA in the ribosome where it forms part of the central protuberance. Binds to the 5S rRNA independently of L5 and L18. Not required for binding of the 5S rRNA/L5/L18 subcomplex to 23S rRNA.[HAMAP-Rule:MF_01336] [RL14_GEOSE] Forms part of two intersubunit bridges in the 70S ribosome (By similarity). Binds to 23S rRNA. [RL23_HALMA] Binds to a specific region on the 23S rRNA. Located at the polypeptide exit tunnel on the outside of the subunit.[HAMAP-Rule:MF_01369] [RS2_THET8] Spans the head-body hinge region of the 30S subunit. Is loosely associated with the 30S subunit.[HAMAP-Rule:MF_00291_B]

See Also

• Ribosome
• Ribosome (Czech)
• Ribosome 3D structures
• Transfer RNA (tRNA)

References

1. ↑ Yusupov MM, Yusupova GZ, Baucom A, Lieberman K, Earnest TN, Cate JH, Noller HF. Crystal structure of the ribosome at 5.5 A resolution. Science. 2001 May 4;292(5518):883-96. Epub 2001 Mar 29. PMID:11283358 doi:10.1126/science.1060089