Toolkit Items

The Aer PAS domain is the FAD-binding sensory domain from the dimeric Escherichia coli aerotaxis receptor Aer. It monitors cellular respiration through a redox-sensitive flavin cofactor and is structurally characterized in the Aer-PAS-GVV variant at 2.4 Å resolution.

The heme PAS domain of Escherichia coli direct oxygen sensor (Ec DOS) is a bacterial heme-binding sensor domain structurally characterized in inactive Fe(3+) and active Fe(2+) states. It acts as a redox-responsive molecular switch in which changes in heme coordination are coupled to conformational rearrangements within the PAS domain.

Co-opting natural allosteric coupling is a protein engineering method that converts proteins into conformational switches by leveraging pre-existing allosteric relationships. The cited literature describes its use to generate proteins that respond to signaling events and thereby enable biosensing or regulated biological function.

New switching mechanisms are a protein engineering approach that introduces stimulus-responsive conformational switching into proteins that previously lacked such behavior. In the cited review, these engineered switches are described as enabling reagent-free biosensing and regulated biological function.

LOV1 is a blue-light-sensing Light-Oxygen-Voltage photosensor domain from Chlamydomonas reinhardtii that occurs in phototropin receptors. In phototropins, LOV1 is paired with LOV2 and a C-terminal serine/threonine kinase domain within a multidomain light-regulated signaling protein.