Structure of a VirD4 coupling protein bound to a VirB type IV secretion machinery

Type IV secretion (T4S) systems are versatile bacterial secretion systems mediating transport of protein and/or DNA. T4S systems are generally composed of 11 VirB proteins and 1 VirD protein (VirD4). The VirB1-11 proteins assemble to form a secretion machinery and a pilus while the VirD4 protein is responsible for substrate recruitment. The structure of VirD4 in isolation is known; however, its structure bound to the VirB1-11 apparatus has not been determined. Here, we purify a T4S system with VirD4 bound, define the biochemical requirements for complex formation and describe the protein–protein interaction network in which VirD4 is involved. We also solve the structure of this complex by negative stain electron microscopy, demonstrating that two copies of VirD4 dimers locate on both sides of the apparatus, in between the VirB4 ATPases. Given the central role of VirD4 in type IV secretion, our study provides mechanistic insights on a process that mediates the dangerous spread of antibiotic resistance genes among bacterial populations.
Source: EMBO Journal - Category: Molecular Biology Authors: Tags: Microbiology, Virology & Host Pathogen Interaction, Structural Biology Articles Source Type: research

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ConclusionThe somatotopy of the hand fascicles in relation to the foot fascicles was anterolateral in patients and volunteers at superior levels but anteromedial in volunteers and mostly anterior in patients at inferior levels. The lip and tongue fascicles generally overlapped. Intracranial tumours displaced the motor fascicles without affecting their relative somatotopy.
Source: NeuroImage: Clinical - Category: Radiology Source Type: research
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Source: NeuroImage: Clinical - Category: Radiology Source Type: research
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Source: European Journal of Radiology - Category: Radiology Source Type: research
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Source: Journal of Thoracic Imaging - Category: Radiology Tags: Editorial Source Type: research
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Source: Journal of Thoracic Imaging - Category: Radiology Tags: Symposium: Imaging of Innovative and Contemporary Thoracic Interventions: State-of-the-Art Source Type: research
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Source: Journal of Thoracic Imaging - Category: Radiology Tags: Symposium: Imaging of Innovative and Contemporary Thoracic Interventions: State-of-the-Art Source Type: research
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Source: Journal of Thoracic Imaging - Category: Radiology Tags: Symposium: Imaging of Innovative and Contemporary Thoracic Interventions: State-of-the-Art Source Type: research
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Source: Journal of Thoracic Imaging - Category: Radiology Tags: Symposium: Imaging of Innovative and Contemporary Thoracic Interventions: State-of-the-Art Source Type: research
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Source: Journal of Thoracic Imaging - Category: Radiology Tags: Symposium: Imaging of Innovative and Contemporary Thoracic Interventions: State-of-the-Art Source Type: research
Purpose: The purpose of this study was to evaluate intermediate and long-term changes in expiratory tracheal collapsibility by computed tomography (CT) in patients with tracheobronchomalacia following surgical treatment with tracheobronchoplasty and to correlate CT findings with clinical findings. Materials and Methods: Between 2003 and 2016, 18 patients with tracheobronchomalacia underwent tracheobronchoplasty and were imaged preoperatively and postoperatively at both intermediate and long-term intervals. Imaging included end-inspiratory and dynamic expiratory phase scans. The cross-sectional area of the airway lumen...
Source: Journal of Thoracic Imaging - Category: Radiology Tags: Original Research Source Type: research
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