Bacterial fimbriae are central to adhesion, colonization, and biofilm formation, yet how related fimbriae systems are structurally and mechanically specialized within the same pathogen remains poorly ...

Download this free 3D print file designed by CiliaBuilder. EM Grid Scaled ModelScaled up and simplified 3D model of EM grids and autogrids for demonstration of preparation process and milling. Content...

Here they combine in vivo imaging with proteomics to characterize a protein complex comprised of Ccdc78 and Ccdc33 that acts at the extreme distal tip of 9 + 2 motile cilia to control tip architecture...

YouTube video by Bui Lab

Motile cilia are unique organelles with the ability to move autonomously. The force generated by beating cilia propels cells and moves fluids. The cil…

Eukaryotic cilia and flagella are thin structures present on the surface of cells, playing vital roles in signaling and cellular motion. Cilia structures rely on intraflagellar transport (IFT), which ...

Ciliogenesis and cilia motility rely on the coordinated actions of diverse dyneins, yet the complexity of these motor proteins in cilia has posed challenges for understanding their specific roles. Tra...

Agrobacterium tumefaciens is a natural genetic engineer that transfers DNA into plants and this is the most frequently applied process for the generation of genetically modified plants. DNA transfer is mediated by a type IV secretion system localized in the cell envelope and extracellular T-pili. We here report the cryo-electron microscopic structures of the T-pilus at 3.2Å resolution and that of the related plasmid pKM101-determined N-pilus at 3Å resolution. Both pili contain a main pilus protein (VirB2 in A. tumefaciens and TraM in pKM101) and phospholipids arranged in a 5-start helical assembly. They contain positively charged amino acids in the pilus lumen and the lipids are positively charged in the T-pilus (phosphatidylcholine) conferring overall positive charge to the lumen. Mutagenesis of the lumen-exposed Arg91 residue in VirB2 resulted in protein destabilization and loss of pilus formation. Our results reveal that different phospholipids can be incorporated into type IV secretion system pili and that the charge of the lumen is of functional importance. ### Competing Interest Statement The authors have declared no competing interest.

Intraflagellar transport for ciliary assembly and maintenance is driven by dynein and kinesins specific for the cilia. It has been shown that anterograde and retrograde transports run on different regions of the doublet microtubule, i.e., separate train tracks. However, little is known about the regulatory mechanism of this selective process. Since the doublet microtubule is known to display specific post-translational modifications of tubulins, i.e. “tubulin code”, for molecular motor regulations, we investigated the motility of ciliary specific dynein-2 under different post-translational modification by coarse-grained molecular dynamics. Our setup allows us to simulate the stochastic stepping behaviors of dynein-2 on un-modified, detyrosinated, poly-glutamylated and poly-glycylated microtubules in silico. Our study revealed that poly-glutamylation can play an inhibitory effect on dynein-2 motility. Our result indicates that poly-glutamylation of the B-tubule of the doublet microtubule can be used as an efficient means to target retrograde intraflagellar transport onto the A-tubule. ### Competing Interest Statement The authors have declared no competing interest.

image image Cryo‐EM structure of the outer dynein arm (ODA) complex attached to the doublet microtubule combined with the coarse‐grained molecular dynamics (MD) simulation reveals the active conformation of the ODA and the activation ...

Nature Structural & Molecular Biology - Primary cilia are isolated from monolayers of mammalian cells in culture for cryo-ET analyses, revealing new features as well as how they differ from...

Cryo-electron microscopy (cryo-EM) maps usually show heterogeneous distributions of B-factors and electron density occupancies and are typically B-factor sharpened to improve their contrast and interpretability at high-resolutions. However, ‘over-sharpening’ due to the application of a single global B-factor can distort processed maps causing connected densities to appear broken and disconnected. This issue limits the interpretability of cryo-EM maps, i.e. ab initio modelling. In this work, we propose 1) approaches to enhance high-resolution features of cryo-EM maps, while preventing map distortions and 2) methods to obtain local B-factors and electron density occupancy maps. These algorithms have as common link the use of the spiral phase transformation and are called LocSpiral, LocBSharpen, LocBFactor and LocOccupancy. Our results, which include improved maps of recent SARS-CoV-2 structures, show that our methods can improve the interpretability and analysis of obtained reconstructions. ### Competing Interest Statement The authors have declared no competing interest.