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From Proteopedia
Crystal Structure of the 30S ribosomal subunit from a KsgA mutant of Thermus thermophilus (HB8)
Structural highlights
Function[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). [RS17_THETH] One of the primary rRNA binding proteins, it binds specifically to the 5'-end of 16S ribosomal RNA (By similarity). [RS18_THETH] Binds as a heterodimer with protein S6 to the central domain of the 16S rRNA, where it helps stabilize the platform of the 30S subunit (By similarity). [RS16_THETH] Binds to the lower part of the body of the 30S subunit, where it stabilizes two of its domains. [RS6_THETH] Located on the outer edge of the platform on the body of the 30S subunit (By similarity). [RS12_THETH] 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 (By similarity).[HAMAP-Rule:MF_00403_B] [RS15_THETH] 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. Forms an intersubunit bridge (bridge B4) with the 23S rRNA of the 50S subunit in the ribosome (By similarity). [RS20_THET8] One of the primary rRNA binding proteins, it binds directly to 16S rRNA where it nucleates assembly of the bottom of the body of the 30S subunit, by binding to several RNA helices of the 16S rRNA.[HAMAP-Rule:MF_00500] [RS8_THETH] One of the primary rRNA binding proteins, it binds directly to 16S rRNA central domain where it helps coordinate assembly of the platform of the 30S subunit (By similarity). [RS10_THETH] Involved in the binding of tRNA to the ribosomes (By similarity). [RS19_THETH] Protein S19 forms a complex with S13 that binds strongly to the 16S ribosomal RNA (By similarity). [RS5_THETH] 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 (By similarity).[HAMAP-Rule:MF_01307_B] Evolutionary ConservationCheck, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedAll organisms incorporate post-transcriptional modifications into ribosomal RNA, influencing ribosome assembly and function in ways that are poorly understood. The most highly conserved modification is the dimethylation of two adenosines near the 3' end of the small subunit rRNA. Lack of these methylations due to deficiency in the KsgA methyltransferase stimulates translational errors during both the initiation and elongation phases of protein synthesis and confers resistance to the antibiotic kasugamycin. Here, we present the X-ray crystal structure of the Thermus thermophilus 30S ribosomal subunit lacking these dimethylations. Our data indicate that the KsgA-directed methylations facilitate structural rearrangements in order to establish a functionally optimum subunit conformation during the final stages of ribosome assembly. Modification of 16S ribosomal RNA by the KsgA methyltransferase restructures the 30S subunit to optimize ribosome function.,Demirci H, Murphy F 4th, Belardinelli R, Kelley AC, Ramakrishnan V, Gregory ST, Dahlberg AE, Jogl G RNA. 2010 Oct 20. PMID:20962038[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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Categories: Thermus thermophilus | Belardinelli, R | Dahlberg, A E | Demirci, H | Gregory, S T | IV, F Murphy | Jogl, G | Kelley, A C | Ramakrishnan, V | 30s ribosomal subunit | Antibiotic resistance | Decoding | Decoding of genetic code | Ksga knock-out | Mrna | Post transcriptional rrna modification | Ribosome | Trna