Biology subjects

Ringler, P.

Publications and source records attributed to Ringler, P..

3 recordsLinked to original sources

bioRxiv2020

High-resolution cryo-EM structure of urease from the pathogen Yersinia enterocolitica

Urease converts urea into ammonia and carbon dioxide and makes urea available as a nitrogen source for all forms of life except animals. In human bacterial pathogens, ureases also aid in the invasion of acidic environments such as the stomach by raising the surrounding pH. Here, we report the structure of urease from the pathogen Yersinia enterocolitica at better than 2 [A] resolution from cryo-electron microscopy. Y. enterocolitica urease is a dodecameric assembly of a trimer of three protein chains, ureA, ureB and ureC. The high data quality enables detailed visualization of the urease bimetal active site and of the impact of radiation damage. Our data are of sufficient quality to support drug development efforts.

molecular biology↗

bioRxiv2019

Two new polymorphic structures of alpha-synuclein solved by cryo-electron microscopy

Intracellular inclusions rich in alpha-synuclein are a hallmark of several neuropathological diseases including Parkinsons disease (PD). We here report two new polymorphic atomic structures of alpha-synuclein fibrils termed polymorphs 2a and 2b, at 3.0 [A] and 3.4 [A] resolution, respectively. These polymorphs show a radically different structure compared to previously reported polymorphs. The new structures have a 10 nm fibril diameter and are composed of two protofilaments which interact via intermolecular salt-bridges between amino acids K45, E57 (polymorph 2a) or E46 (polymorph 2b). The non-amyloid component (NAC) region of alpha-synuclein is fully buried by previously non-described interactions with the N-terminus. A hydrophobic cleft, the location of familial PD mutation sites, and the nature of the protofilament interface now invite to formulate hypotheses about fibril formation, growth and stability. Impact statementTwo new polymorphic structures of recombinant human alpha-synuclein fibrils show striking differences to previous structures, while familial PD mutation sites remain crucial for protofilament interaction and fibril stability.

neuroscience↗

bioRxiv2018

Cryo-EM structure of alpha-synuclein fibrils

Intracellular inclusions of alpha-synuclein are the neuropathological hallmark of progressive disorders called synucleinopathies. Alpha-synuclein fibrils are associated with transmissive cell-to-cell propagation of pathology. We report the structure of an alpha-synuclein fibril (residues 1-121) determined by cryo-electron microscopy at 3.4[A] resolution. Two protofilaments form a polar fibril composed of staggered {beta}-strands. The backbone of residues 38 to 95, including the fibril core and the non-amyloid component region, are well resolved in the EM map. Residues 50-57, containing three mutation sites associated with familial synucleinopathies, form the interface between the two protofilaments and contribute to fibril stability. A hydrophobic cleft may have implications for fibril elongation, and inform the rational design of molecules for diagnosis and treatment of synucleinopathies.

neuroscience↗