Synthetic biology-inspired cell engineering in diagnosis, treatment, and drug development.

The fast-developing synthetic biology (SB) has provided many genetic tools to reprogram and engineer cells for improved performance, novel functions, and diverse applications. Such cell engineering resources can play a critical role in the research and development of novel therapeutics. However, there are certain limitations and challenges in applying genetically engineered cells in clinical practice. This literature review updates the recent advances in biomedical applications, including diagnosis, treatment, and drug development, of SB-inspired cell engineering. It describes technologies and relevant examples in a clinical and experimental setup that may significantly impact the biomedicine field. At last, this review concludes the results with future directions to optimize the performances of synthetic gene circuits to regulate the therapeutic activities of cell-based tools in specific diseases.

Discovery of a Unique Structural Motif in Lanthipeptide Synthetases for Substrate Binding and Interdomain Interactions.

Class III lanthipeptide synthetases catalyze the formation of lanthionine/methyllanthionine and labionin crosslinks. We present here the 2.40 Šresolution structure of the kinase domain of a class III lanthipeptide synthetase CurKC from the biosynthesis of curvopeptin. A unique structural subunit for leader binding, named leader recognition domain (LRD), was identified. The LRD of CurKC is responsible for the recognition of the leader peptide and for mediating interactions between the lyase and kinase domains. LRDs are highly conserved among the kinase domains of class III and class IV lanthipeptide synthetases. The discovery of LRDs provides insight into the substrate recognition and domain organization in multidomain lanthipeptide synthetases.

Conformational remodeling enhances activity of lanthipeptide zinc-metallopeptidases.

Lanthipeptides are an important group of natural products with diverse biological functions, and their biosynthesis requires the removal of N-terminal leader peptides (LPs) by designated proteases. LanPM1 enzymes, a subgroup of M1 zinc-metallopeptidases, have been recently identified as bifunctional proteases with both endo- and aminopeptidase activities to remove LPs of class III and class IV lanthipeptides. Herein, we report the biochemical and structural characterization of EryP as the LanPM1 enzyme from the biosynthesis of class III lanthipeptide erythreapeptin. We determined X-ray crystal structures of EryP in three conformational states, the open, intermediate and closed states, and identified a unique interdomain Ca2+ binding site as a regulatory element that modulates its domain dynamics and proteolytic activity. Inspired by this regulatory Ca2+ binding, we developed a strategy to engineer LanPM1 enzymes for enhanced catalytic activities by strengthening interdomain associations and driving the conformational equilibrium toward their closed forms.