Download MendeleyState-dependent motion of a genetically encoded fluorescent biosensor.
Rosen, P.C., Horwitz, S.M., Brooks, D.J., Kim, E., Ambarian, J.A., Waidmann, L., Davis, K.M., Yellen, G.(2025) Proc Natl Acad Sci U S A 122: e2426324122-e2426324122
- PubMed: 40048274
- DOI: https://doi.org/10.1073/pnas.2426324122
- Primary Citation of Related Structures:
9EBW, 9EBX - PubMed Abstract:
Genetically encoded biosensors can measure biochemical properties such as small-molecule concentrations with single-cell resolution, even in vivo. Despite their utility, these sensors are "black boxes": Very little is known about the structures of their low- and high-fluorescence states or what features are required to transition between them. We used LiLac, a lactate biosensor with a quantitative fluorescence-lifetime readout, as a model system to address these questions. X-ray crystal structures and engineered high-affinity metal bridges demonstrate that LiLac exhibits a large interdomain twist motion that pulls the fluorescent protein away from a "sealed," high-lifetime state in the absence of lactate to a "cracked," low-lifetime state in its presence. Understanding the structures and dynamics of LiLac will help to think about and engineer other fluorescent biosensors.
Organizational Affiliation:
Department of Neurobiology, Harvard Medical School, Boston, MA 02115.
