The LNR (Lin-12/Notch repeat) domain is found in three tandem copies in Notch related proteins. The structure of the domain has been determined by NMR [1] and was shown to contain three disulphide bonds and coordinate a calcium ion. Three repeats are also found in the PAPP-A peptidase [2].

1: Nuclear magnetic resonance structure of a prototype Lin12-Notch repeat module from human Notch1. Vardar D, North CL, Sanchez-Irizarry C, Aster JC, Blacklow SC; Biochemistry. 2003;42:7061-7067. PMID:12795601

2: The Lin12-notch repeats of pregnancy-associated plasma protein-A bind calcium and determine its proteolytic specificity. Boldt HB, Kjaer-Sorensen K, Overgaard MT, Weyer K, Poulsen CB, Sottrup-Jensen L, Conover CA, Giudice LC, Oxvig C; J Biol Chem. 2004;279:38525-38531. PMID:15262980