https://www.molmicro.hu-berlin.de/news.htmlPapers, preprints, grants and lab news from the Erhardt lab (Molecular Microbiology, Humboldt-Universität zu Berlin).enhttps://www.molmicro.hu-berlin.de/news.html#2026-druantiahttps://www.molmicro.hu-berlin.de/news.html#2026-druantiaTue, 22 Sep 2026 00:00:00 +0000PaperEscherichia coli. Its two proteins, DruE and DruH, clear phage infections without harming the host cell. DruE forms a dimer that binds exposed single-stranded DNA and unwinds DNA with 3′-to-5′ directionality, using lock, wedge and clamp elements for strand separation. DruH interacts indirectly with DruE and other host proteins in uninfected cells; infection dissociates the complex. These results identify exposed single-stranded DNA as a trigger of bacterial immunity.]]>https://www.molmicro.hu-berlin.de/news.html#2026-phd-giralthttps://www.molmicro.hu-berlin.de/news.html#2026-phd-giraltMon, 24 Aug 2026 00:00:00 +0000LabSalmonella”. Congratulations, Dr. Giralt Zúñiga.]]>https://www.molmicro.hu-berlin.de/news.html#2026-preprint-cost-benefithttps://www.molmicro.hu-berlin.de/news.html#2026-preprint-cost-benefitThu, 20 Aug 2026 00:00:00 +0000PreprintflhDC of Salmonella enterica from inducible or constitutive promoters and obtained strains from nearly non-flagellated to hyperflagellated cells. More flagella reduced the growth rate: the flagellar share of the proteome grew mainly at the expense of ribosomes, and flagellin synthesis was the largest cost. More flagella also improved spreading, swimming speed and competitive fitness in structured environments. A proteome-allocation model predicts that the benefit of motility saturates near a flagellar investment of 3% of the proteome. Try the interactive motility simulation: strains with fewer or more flagella than the wild type swim side by side, in liquid and in agarose.]]>https://www.molmicro.hu-berlin.de/news.html#2026-preprint-bactomatehttps://www.molmicro.hu-berlin.de/news.html#2026-preprint-bactomateThu, 06 Aug 2026 00:00:00 +0000Preprinthttps://www.molmicro.hu-berlin.de/news.html#2026-preprint-flagella-numberhttps://www.molmicro.hu-berlin.de/news.html#2026-preprint-flagella-numberFri, 10 Jul 2026 00:00:00 +0000PreprintSalmonella cells over time and described the data with a stochastic model. In the model, an RflP-dependent regulatory memory sets a target number of flagella, and synthesis, partitioning at division and growth determine the distribution around this target. The fitted model predicted the flagellar number in a nutrient condition that was not used for fitting.]]>https://www.molmicro.hu-berlin.de/news.html#2026-trnahttps://www.molmicro.hu-berlin.de/news.html#2026-trnaMon, 22 Jun 2026 00:00:00 +0000PaperTyr and (ms²)i⁶A at position 37. E. coli that lacked both modifications showed a severe growth defect, increased +1 frameshifting at tyrosine codons and protein aggregation. The functional interplay is conserved in Schizosaccharomyces pombe.]]>https://www.molmicro.hu-berlin.de/news.html#2026-preprint-intracellular-flagellahttps://www.molmicro.hu-berlin.de/news.html#2026-preprint-intracellular-flagellaTue, 16 Jun 2026 00:00:00 +0000PreprintSalmonella assembles before it enters epithelial cells. The bacteria keep these flagella during invasion. Inside the Salmonella-containing vacuole the flagella are disassembled; in the cytosol, autophagy targets them. The human-restricted serovar Paratyphi A uses its preassembled flagella for motility inside the host cell and to escape from the vacuole.]]>https://www.molmicro.hu-berlin.de/news.html#2026-preprint-ancestral-flagellumhttps://www.molmicro.hu-berlin.de/news.html#2026-preprint-ancestral-flagellumFri, 12 Jun 2026 00:00:00 +0000Preprinthttps://www.molmicro.hu-berlin.de/news.html#2026-preprint-druantia-mechanismhttps://www.molmicro.hu-berlin.de/news.html#2026-preprint-druantia-mechanismWed, 13 May 2026 00:00:00 +0000Preprinthttps://www.molmicro.hu-berlin.de/news.html#2026-vibrio-sheathhttps://www.molmicro.hu-berlin.de/news.html#2026-vibrio-sheathThu, 23 Apr 2026 00:00:00 +0000PaperVibrio species, a membranous sheath that extends from the outer membrane encloses the flagellar filament. Together with the group of Julien Bergeron, we combined cryo-EM, cryo-electron tomography and genetics to resolve the sheathed flagellum of Vibrio alginolyticus. The filament is a canonical 11-stranded supercoil of the flagellin FlaD2 inside a bilayered sheath. The filament surface is highly electronegative. This suggests that electrostatic repulsion between filament and sheath reduces friction during rotation. The cap protein FliD contains an additional domain that may coordinate sheath assembly with filament elongation.]]>https://www.molmicro.hu-berlin.de/news.html#2026-phd-einenkelhttps://www.molmicro.hu-berlin.de/news.html#2026-phd-einenkelFri, 17 Apr 2026 00:00:00 +0000Labhttps://www.molmicro.hu-berlin.de/news.html#2026-ecishttps://www.molmicro.hu-berlin.de/news.html#2026-ecisThu, 16 Apr 2026 00:00:00 +0000PaperS. enterica subsp. salamae. The structure shows a sheath architecture that differs from that of other contractile injection systems, a cage-like shell around the central spike and an associated integral membrane protein. Our data indicate that the system interacts with the inner membrane. Based on these structural features, we identified a previously unannotated cluster of contractile injection systems.]]>https://www.molmicro.hu-berlin.de/news.html#2026-preprint-nissle-flagellinhttps://www.molmicro.hu-berlin.de/news.html#2026-preprint-nissle-flagellinMon, 30 Mar 2026 00:00:00 +0000PreprintE. coli Nissle 1917. Its crystal structure at 1.2 Å shows a hypervariable region that forms an outer domain around the conserved filament core. Removal of the linker to this region reduced protein stability and motility, whereas recognition by TLR5 changed only moderately.]]>https://www.molmicro.hu-berlin.de/news.html#2025-conjugationhttps://www.molmicro.hu-berlin.de/news.html#2025-conjugationMon, 15 Dec 2025 00:00:00 +0000PaperE. coli biofilms in microfluidic chambers. Conjugation was efficient until the cell density reached a threshold associated with high matrix secretion. Conjugative pili enabled matrix-deficient cells to form dense biofilms with increased antibiotic and phage tolerance. Plasmid-carrying cells dispersed less than plasmid-free cells.]]>https://www.molmicro.hu-berlin.de/news.html#2025-fliihttps://www.molmicro.hu-berlin.de/news.html#2025-fliiFri, 05 Dec 2025 00:00:00 +0000PaperSalmonella strains with mutations in the catalytic domain of the ATPase FliI. Minimal ATPase activity was sufficient for early export and hook-basal-body assembly. Efficient substrate-specificity switching and export of late substrates required near-wild-type activity. The mutants showed delayed class 3 gene expression, prolonged early secretion and impaired filament assembly, although FliI localisation and oligomerisation were normal. These data link ATPase activity to substrate switching in type-III secretion.]]>https://www.molmicro.hu-berlin.de/news.html#2025-einsteinhttps://www.molmicro.hu-berlin.de/news.html#2025-einsteinWed, 03 Dec 2025 00:00:00 +0000Granthttps://www.molmicro.hu-berlin.de/news.html#2025-mmbrhttps://www.molmicro.hu-berlin.de/news.html#2025-mmbrThu, 20 Nov 2025 00:00:00 +0000ReviewMicrobiology and Molecular Biology Reviews covers recent progress on the structure, assembly and regulation of the flagellum: hierarchical gene regulation, motor mechanics and new structures of the core components. The review also discusses the legacy of Howard Berg and open questions that require single-cell observations.]]>https://www.molmicro.hu-berlin.de/news.html#2025-spp2389https://www.molmicro.hu-berlin.de/news.html#2025-spp2389Fri, 22 Aug 2025 00:00:00 +0000Granthttps://www.molmicro.hu-berlin.de/news.html#2025-fliohttps://www.molmicro.hu-berlin.de/news.html#2025-flioThu, 21 Aug 2025 00:00:00 +0000PaperCampylobacter jejuni, FliO and its AMIN domain are needed for efficient flagellation, stability of FlhB and host colonisation.]]>https://www.molmicro.hu-berlin.de/news.html#2025-yebchttps://www.molmicro.hu-berlin.de/news.html#2025-yebcMon, 07 Jul 2025 00:00:00 +0000PaperStreptococcus pyogenes. Experiments in Salmonella Typhimurium and in an in vitro translation system support this function.]]>