Hundreds of papers have been published on Nod1 and Nod2, two intracellular proteins that recognize bacterial cell-wall components and play key roles in innate immunity and possibly Crohn disease. Stephen Girardin and colleagues at the Institut Pasteur in Paris recently identified the residues in human Nod1 responsible for recognizing the muropeptide TriDAP.1 Faculty of 1000 reviewer Richard Stevens at Harvard Medical School and Brigham and Women's Hospital calls the article "a tour de force" that moves several fields forward.
"The authors swapped the leucine-rich repeat (LRR) domain in Nod1 and Nod2, and then carried out a series of point mutations to identify the critical residues in Nod1 that recognize bacteria. The crystal structures of the Nod1 and Nod2 proteins have not been deduced, so the authors had to make educated guesses as to what residues to mutate.
"Splice variants of Nod1 have been identified, and one of the regions that ...
