Evolution of CEACAM pathogen decoy receptors in primates.

Background: CEACAM1 in leukocytes controls cell activation during inflammation. This and its expression in epithelial cells led to frequent independent appropriation of CEACAM1 as receptor by pathogens in humans and other species to gain host access and to downregulate its immune response. As a countermeasure, decoy receptors with CEACAM1-like pathogen-binding domains evolved.

A DARPin promotes faster onset of botulinum neurotoxin A1 action.

In this study, we characterize Designed Ankyrin Repeat Proteins (DARPins) as investigative tools to probe botulinum neurotoxin A1 (BoNT/A1) structure and function. We identify DARPin-F5 that completely blocks SNAP25 substrate cleavage by BoNT/A1 in vitro. X-ray crystallography reveals that DARPin-F5 inhibits BoNT/A1 activity by interacting with a substrate-binding region between the α- and β-exosite.

Solution NMR assignments and structure for the dimeric kinesin neck domain.

Kinesin is a motor protein, comprised of two heavy and two light chains that transports cargo along the cytoskeletal microtubule filament network. The heavy chain has a neck domain connecting the ATPase motor head responsible for walking along microtubules, with the stalk and subsequent tail domains that bind cargo. The neck domain consists of a coiled coli homodimer with about five heptad repeats, preceded by a linker region that joins to the ATPase head.