Allosteric transitions direct protein tagging by PafA, the prokaryotic ubiquitin-like protein (Pup) ligase

Abstract

Background: The interaction of PafA, the prokaryotic ubiquitin-like ligase, with its protein substrates is poorly understood. Results: Measurements of PafA kinetics reveal cooperative substrate binding and experiments with engineered substrates suggest that PafA forms dimers. Conclusion: The PafA enzymatic mechanism involves allosteric transitions. Significance: PafA interaction with its target substrates is regulated at the enzyme level. © 2013 by The American Society for Biochemistry and Molecular Biology, Inc.