The Fluc family is a set of small membrane proteins forming F(-)-specific electrodiffusive ion channels that rescue microorganisms from F(-) toxicity during exposure to weakly acidic environments. The functional channel is built as a dual-topology homodimer with twofold symmetry parallel to the membrane plane. Fluc channels are blocked by nanomolar-affinity fibronectin-domain monobodies originally selected from phage-display libraries. The unusual symmetrical antiparallel dimeric architecture of Flucs demands that the two chemically equivalent monobody-binding epitopes reside on opposite ends of the channel, a double-sided blocking situation that has never before presented itself in ion channel biophysics. However, it is not known if both sites can be simultaneously occupied, and if so, whether monobodies bind independently or cooperatively to their transmembrane epitopes. Here, we use direct monobody-binding assays and single-channel recordings of a Fluc channel homolog to reveal a novel trimolecular blocking behavior that reveals a doubly occupied blocked state. Kinetic analysis of single-channel recordings made with monobody on both sides of the membrane shows substantial negative cooperativity between the two blocking sites.
This research output has an Altmetric Attention Score of 1. This is our high-level measure of the quality and quantity of online attention that it has received. This Attention Score, as well as the ranking and number of research outputs shown below, was calculated when the research output was last mentioned on 07 May 2015.
All research outputs
#24,782,047
of 34,400,738 outputs
Outputs from Proceedings of the National Academy of Sciences of the United States of America
#109,116
of 118,992 outputs
Outputs of similar age
#208,524
of 308,235 outputs
Outputs of similar age from Proceedings of the National Academy of Sciences of the United States of America
#790
of 914 outputs
Altmetric has tracked 34,400,738 research outputs across all sources so far. This one is in the 19th percentile – i.e., 19% of other outputs scored the same or lower than it.
So far Altmetric has tracked 118,992 research outputs from this source. They typically receive a lot more attention than average, with a mean Attention Score of 40.1. This one is in the 4th percentile – i.e., 4% of its peers scored the same or lower than it.
Older research outputs will score higher simply because they've had more time to accumulate mentions. To account for age we can compare this Altmetric Attention Score to the 308,235 tracked outputs that were published within six weeks on either side of this one in any source. This one is in the 25th percentile – i.e., 25% of its contemporaries scored the same or lower than it.
We're also able to compare this research output to 914 others from the same source and published within six weeks on either side of this one. This one is in the 9th percentile – i.e., 9% of its contemporaries scored the same or lower than it.
