In this issue of Structure, Zhang et al.1 report high-resolution cryo-electron microscopy (cryo-EM) structures of the human WDR11-FAM91A1-C17orf75 complex, establishing C17orf75 as an integral core subunit and revealing the molecular basis by which this ternary machinery coordinates retrograde vesicle tethering and selective sorting of super-acidic-cluster-containing cargoes.
In this issue of Structure, Hylton et al.1 present MOSAIC, an accessible, acquisition-software-agnostic framework for montage cryo-electron tomography (cryo-ET). By streamlining acquisition and stitching workflows, MOSAIC lowers technical barriers to wide-field imaging, maximizing data recovery from cryolamellae and making meso-scale cellular architecture broadly accessible across diverse cryo-ET platforms.
Candida auris is an emerging multidrug-resistant fungal pathogen responsible for severe healthcare-associated infections worldwide; yet, the molecular architecture of its translational apparatus remains poorly understood. Here, we present a structural and functional analysis of the C. auris ribosome. Using in-house rRNA sequencing, we found that C. auris rRNA displays substantial divergence, including the lowest 18S rRNA identity among the pathogenic Candida species examined and an unusual substitution at a functionally important nucleotide in helix h31 of the small subunit P-site region. To define the structural basis of these differences, we determined single-particle cryo-electron microscopy structures of the vacant C. auris 80S ribosome and its complexes with cycloheximide (CHX), blasticidin S (BLS), and geneticin (G418). Together with cell-free translation inhibition assays, these results establish a structural framework for understanding the C. auris ribosome and reveal how local ribosomal variation within a conserved fungal scaffold can be associated with species-specific inhibitor responses.
In a recent issue of Nature Chemical Biology, Nguy et al.1 report the discovery of an array of cytochrome P450 enzymes that challenge the long-standing view that P450 hemes must be coordinated by a cysteine thiolate. Many of these "noncanonical" P450s instead use serine or selenocysteine ligands. The characterization of two selected variants revealed distinct structural and spectroscopic features.
