Thomas C Marlovits

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Type III secretion systems (TTSSs) mediate translocation of virulence factors into host cells. We report the 17-angstrom resolution structures of a central component of Salmonella typhimurium TTSS, the needle complex, and its assembly precursor, the bacterial envelope-anchored base. Both the base and the fully assembled needle complex adopted multiple(More)
Type III secretion systems (T3SSs) are essential virulence factors used by many Gram-negative bacteria to inject proteins that make eukaryotic host cells accessible to invasion. The T3SS core structure, the needle complex (NC), is a ~3.5 megadalton-sized, oligomeric, membrane-embedded complex. Analyzing cryo-electron microscopy images of top views of NCs or(More)
One of the most exciting developments in the field of bacterial pathogenesis in recent years is the discovery that many pathogens utilize complex nanomachines to deliver bacterially encoded effector proteins into target eukaryotic cells. These effector proteins modulate a variety of cellular functions for the pathogen's benefit. One of these(More)
Assembly of multi-component supramolecular machines is fundamental to biology, yet in most cases, assembly pathways and their control are poorly understood. An example is the type III secretion machine, which mediates the transfer of bacterial virulence proteins into host cells. A central component of this nanomachine is the needle complex or injectisome,(More)
Kinetochores are megadalton-sized protein complexes that mediate chromosome-microtubule interactions in eukaryotes. How kinetochore assembly is triggered specifically on centromeric chromatin is poorly understood. Here we use biochemical reconstitution experiments alongside genetic and structural analysis to delineate the contributions of(More)
Type-3 secretion systems are sophisticated syringe-like nanomachines present in many animal and plant Gram-negative pathogens. They are capable of translocating an arsenal of specific bacterial toxins (effector proteins) from the prokaryotic cytoplasm across the three biological membranes directly into the eukaryotic cytosol, some of which modulate host(More)
The correct organization of single subunits of multi-protein machines in a three dimensional context is critical for their functionality. Type III secretion systems (T3SS) are molecular machines with the capacity to deliver bacterial effector proteins into host cells and are fundamental for the biology of many pathogenic or symbiotic bacteria. A central(More)
G proteins are critical for the regulation of membrane protein function and signal transduction. Nevertheless, coupling between G proteins and membrane proteins with multiple membrane-spanning domains has so far been observed only in higher organisms. Here we show that the polytopic membrane protein FeoB, which is essential for Fe(II) uptake in bacteria,(More)
The type III secretion system (T3SS) is essential for the infectivity of many pathogenic Gram-negative bacteria. The T3SS contains proteins that form a channel in the inner and outer bacterial membranes, as well as an extracellular needle that is used for transporting and injecting effector proteins into a host cell. The homology between the T3SS and the(More)
Human rhinovirus serotype 2 (HRV2) belongs to the minor group of HRVs that bind to members of the LDL-receptor family including the very low density lipoprotein (VLDL)-receptor (VLDL-R). We have determined the structures of the complex between HRV2 and soluble fragments of the VLDL-R to 15 A resolution by cryo-electron microscopy. The receptor fragments,(More)