Aminoglycoside ribosome interactions reveal novel conformational states at ambient temperature
Category
Published on
Type
posted-content
Author
Mary E. O'Sullivan and Frederic Poitevin and Raymond G. Sierra and Cornelius Gati and E. Han Dao and Yashas Rao and Fulya Aksit and Halilibrahim Ciftci and Nicholas Corsepius and Robert Greenhouse and Brandon Hayes and Mark S. Hunter and Mengling Liang and Alex McGurk and Paul Mbgam and Trevor Obrinsky and Fatima Pardo-Avila and Matt Seaberg and Alan G. Cheng and Anthony J. Ricci and Hasan DeMirci
Citation
O’Sullivan, M.E. et al., 2018. Aminoglycoside ribosome interactions reveal novel conformational states at ambient temperature. Available at: http://dx.doi.org/10.1101/372144.
Abstract
The bacterial 30S ribosomal subunit is a primary antibiotic target. Despite decades of discovery, the mechanisms by which antibiotic binding induces ribosomal dysfunction are not fully understood. Ambient temperature crystallographic techniques allow more biologically relevant investigation of how local antibiotic binding site interactions trigger global subunit rearrangements that perturb protein synthesis. Here, the structural effects of 2-deoxystreptamine (paromomycin and sisomicin), a novel sisomicin derivative, N1-methyl sulfonyl sisomicin (N1MS) and the non-deoxystreptamine (streptomycin) aminoglycosides on the ribosome at ambient and cryogenic temperatures were examined. Comparative studies led to three main observations. First, individual aminoglycoside-ribosome interactions in the decoding center were similar for cryogenic vs ambient temperature structures. Second, analysis of a highly conserved GGAA tetraloop of h45 revealed aminoglycoside-specific conformational changes, which are affected by temperature only for N1MS. We report the h44/h45 interface in varying states, that is, engaged, disengaged and in equilibrium. Thirdly, we observe aminoglycoside-induced effects on 30S domain closure, including a novel intermediary closure state, which is also sensitive to temperature. Analysis of three ambient and five cryogenic crystallography datasets reveal a correlation between h44/h45 engagement and domain closure. These observations illustrate the role of ambient temperature crystallography in identifying dynamic mechanisms of ribosomal dysfunction induced by local drug-binding site interactions. Together these data identify tertiary ribosomal structural changes induced by aminoglycoside binding that provides functional insight and targets for drug design.
DOI
Funding
NSF-STC Biology with X-ray Lasers (NSF-1231306)
