protein folding
- Research Article | Molecular Biology and PhysiologySequential Translocation of Polypeptides across the Bacterial Outer Membrane through the Trimeric Autotransporter Pathway
Trimeric autotransporter adhesins (TAAs) are specialized bacterial outer membrane proteins consisting of three identical subunits. TAAs contain large extracellular domains that trimerize and promote virulence, but the mechanism by which they are secreted is poorly understood. We found that the extracellular domains of a native TAA were secreted rapidly but that disordered and artificially folded polypeptides fused to native passenger...
- Observation | Molecular Biology and PhysiologyInterplay between the Hsp90 Chaperone and the HslVU Protease To Regulate the Level of an Essential Protein in Shewanella oneidensis
Maintaining a healthy proteome is essential in every living cell from bacteria to humans. For example, proteostasis (protein homeostasis) imbalance in humans leads to devastating diseases, including neurodegenerative diseases and cancers. Therefore, proteins need to be assisted from their synthesis to their native folding and ultimately to their degradation. To ensure efficient protein turnover, cells possess an intricate network of...
- Research Article | Molecular Biology and PhysiologyStructure and Mechanism of LcpA, a Phosphotransferase That Mediates Glycosylation of a Gram-Positive Bacterial Cell Wall-Anchored Protein
In Gram-positive bacteria, the conserved LCP family enzymes studied to date are known to attach glycopolymers, including wall teichoic acid, to the cell envelope. It is unknown if these enzymes catalyze glycosylation of surface proteins. We show here in the actinobacterium Actinomyces oris by X-ray crystallography and biochemical analyses that A. oris LcpA is...
- Research Article | Molecular Biology and PhysiologyThe Chaperone and Redox Properties of CnoX Chaperedoxins Are Tailored to the Proteostatic Needs of Bacterial Species
How proteins are protected from stress-induced aggregation is a crucial question in biology and a long-standing mystery. While a long series of landmark studies have provided important contributions to our current understanding of the proteostasis network, key fundamental questions remain unsolved. In this study, we show that the intrinsic features of the chaperedoxin CnoX, a folding factor that combines chaperone and redox protective...