5o2r
From Proteopedia
Cryo-EM structure of the proline-rich antimicrobial peptide Api137 bound to the terminating ribosome
Structural highlights
FunctionRL2_ECOLI One of the primary rRNA binding proteins. Located near the base of the L1 stalk, it is probably also mobile. 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 highly controversial.[HAMAP-Rule:MF_01320_B] In the E.coli 70S ribosome in the initiation state it has been modeled to make several contacts with the 16S rRNA (forming bridge B7b, PubMed:12809609); these contacts are broken in the model with bound EF-G.[HAMAP-Rule:MF_01320_B] Publication Abstract from PubMedMany antibiotics stop bacterial growth by inhibiting different steps of protein synthesis. However, no specific inhibitors of translation termination are known. Proline-rich antimicrobial peptides, a component of the antibacterial defense system of multicellular organisms, interfere with bacterial growth by inhibiting translation. Here we show that Api137, a derivative of the insect-produced antimicrobial peptide apidaecin, arrests terminating ribosomes using a unique mechanism of action. Api137 binds to the Escherichia coli ribosome and traps release factor (RF) RF1 or RF2 subsequent to the release of the nascent polypeptide chain. A high-resolution cryo-EM structure of the ribosome complexed with RF1 and Api137 reveals the molecular interactions that lead to RF trapping. Api137-mediated depletion of the cellular pool of free release factors causes the majority of ribosomes to stall at stop codons before polypeptide release, thereby resulting in a global shutdown of translation termination. An antimicrobial peptide that inhibits translation by trapping release factors on the ribosome.,Florin T, Maracci C, Graf M, Karki P, Klepacki D, Berninghausen O, Beckmann R, Vazquez-Laslop N, Wilson DN, Rodnina MV, Mankin AS Nat Struct Mol Biol. 2017 Jul 24. doi: 10.1038/nsmb.3439. PMID:28741611[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
| ||||||||||||||||||
