1kd1
From Proteopedia
Co-crystal Structure of Spiramycin bound to the 50S Ribosomal Subunit of Haloarcula marismortui
Structural highlights
FunctionRL2_HALMA 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_A] Evolutionary ConservationCheck, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedCrystal structures of the Haloarcula marismortui large ribosomal subunit complexed with the 16-membered macrolide antibiotics carbomycin A, spiramycin, and tylosin and a 15-membered macrolide, azithromycin, show that they bind in the polypeptide exit tunnel adjacent to the peptidyl transferase center. Their location suggests that they inhibit protein synthesis by blocking the egress of nascent polypeptides. The saccharide branch attached to C5 of the lactone rings extends toward the peptidyl transferase center, and the isobutyrate extension of the carbomycin A disaccharide overlaps the A-site. Unexpectedly, a reversible covalent bond forms between the ethylaldehyde substituent at the C6 position of the 16-membered macrolides and the N6 of A2103 (A2062, E. coli). Mutations in 23S rRNA that result in clinical resistance render the binding site less complementary to macrolides. The structures of four macrolide antibiotics bound to the large ribosomal subunit.,Hansen JL, Ippolito JA, Ban N, Nissen P, Moore PB, Steitz TA Mol Cell. 2002 Jul;10(1):117-28. PMID:12150912[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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