Publications by authors named "Ronnald Vollrath"
Article Synopsis
- The study presents a detailed cryo-EM structure of a UBE1L-UBE2L6 complex bound to ISG15, highlighting the initial steps in recognizing ISG15 and recruiting UBE2L6.
- It utilizes viral proteins from SARS-CoV-2 and influenza B to validate the significance of the ISG15 C-terminal region in the adenylation reaction.
- The research also explores the interactions between UBE1L-ISG15 and UBE1L-UBE2L6, enabling the creation of mutants that affect important signalling pathways in the innate immune response.
Ubiquitin (Ub) chain formation by homologous to E6AP C-terminus (HECT)-family E3 ligases regulates vast biology, yet the structural mechanisms remain unknown. We used chemistry and cryo-electron microscopy (cryo-EM) to visualize stable mimics of the intermediates along K48-linked Ub chain formation by the human E3, UBR5. The structural data reveal a ≈ 620 kDa UBR5 dimer as the functional unit, comprising a scaffold with flexibly tethered Ub-associated (UBA) domains, and elaborately arranged HECT domains.
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- Yeast fatty acid synthase (FAS) is a large, complex protein structure formed by two intertwined subunits, crucial for fatty acid production.
- Recent research uncovered that the assembly of FAS begins during protein synthesis when the β-subunit interacts with the growing α-subunit, revealing its assembly process is sensitive to changes in amino acids.
- The study also notes that assembly can start at various points, and highlights the role of a dimeric subunit that helps coordinate complex formation and modifications, providing insights for future biotechnological applications.
Ubiquitin (Ub)-mediated proteolysis is a fundamental mechanism used by eukaryotic cells to maintain homeostasis and protein quality, and to control timing in biological processes. Two essential aspects of Ub regulation are conjugation through E1-E2-E3 enzymatic cascades and recognition by Ub-binding domains. An emerging theme in the Ub field is that these 2 properties are often amalgamated in conjugation enzymes.
View Article and Find Full Text PDFPhosphate is an essential component of all cells that must be taken up from the environment. Prokaryotes commonly secrete alkaline phosphatases (APs) to recruit phosphate from organic compounds by hydrolysis. In this study, the AP from Halobacterium salinarum, an archaeon that lives in a saturated salt environment, has been functionally and structurally characterized.
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- The fungal type I fatty acid synthase (FAS) is a large enzyme complex responsible for creating long acyl chains, with a key modification required for its activation.
- An important enzyme, phosphopantetheine transferase (PPT), modifies the acyl carrier domain (ACP) but is physically separated in the FAS structure, suggesting that activation must occur before the complex fully assembles.
- The study focuses on understanding the activation process and assembly pathway of FAS by examining the structure and function of the PPT in the yeast Saccharomyces cerevisiae, both as part of the larger complex and on its own.