currentina

Currentina is a hypothetical integral membrane protein proposed to participate in extracellular electron transfer in electroactive microorganisms. The name follows the common protein suffix -ina and is used in theoretical discussions to illustrate mechanisms of redox signaling across the cell envelope. In proposed models, Currentina is encoded by a gene cluster adjacent to other redox-related genes and is predicted to be stable in the inner membrane with multiple transmembrane helices.

Predicted structure: Currentina is described as having six to eight transmembrane helices with a conserved redox-active motif in an extracellular loop. Some models assign it a periplasmic-facing domain that could bind redox cofactors such as heme or flavin, though experimental evidence is lacking.

Proposed function: In speculative scenarios, Currentina acts as a conduit for electrons between cytoplasmic electron carriers and external acceptors, coordinating with outer-surface cytochromes to facilitate long-range electron transfer. It may be regulated by membrane potential and environmental redox conditions, integrating into broader electron transfer networks.

Discovery and status: The term Currentina originated in theoretical and computational studies of microbial electricity and has not been validated by biochemical or structural experiments in peer-reviewed work. As such, it remains a speculative component of proposed electron-transfer pathways.

Significance: If confirmed, Currentina could inform the design of bioelectronic devices and synthetic biology circuits that exploit microbial electron transfer, potentially enabling new approaches to energy generation and biosensing.