Membrane binding of ribosomes occurs at SecYE-based sites in the Archaea Haloferax volcanii.

摘要: Whereas ribosomes bind to membranes at eukaryal Sec61abg and bacterial SecYEG sites, ribosomal membrane binding has yet be studied in Archaea. Accordingly, functional inverted vesicles were prepared from the halophilic archaea Haloferax volcanii. The ability of was determined using a flotation approach. Proteolytic pretreatment vesicles, as well quantitative analyses, revealed existence proteinaceous ribosome receptor, with affinity being comparable that found Eukarya Bacteria. Inverted cells expressing chimeras SecE or SecY fused cytoplasmically oriented cellulose-binding domain displayed reduced due steric hindrance. Pretreatment cellulose drastically chimera-containing but not wild-type vesicles. Thus, Bacteria, Archaea occurs Sec-based sites. However, unlike situation other domains Life, haloarchaea requires molar concentrations salt. Structural information on ‐ Sec complexes may provide insight into this high salt-dependent binding. q 2004 Elsevier Ltd. All rights reserved.