6a97

Publication Abstract from PubMed

The MILL family, composed of MILL1 and MILL2, is a group of nonclassical MHC class I molecules that occur in some orders of mammals. It has been reported that mouse MILL2 is involved in wound healing; however, the molecular mechanisms remain unknown. Here, we determine the crystal structure of MILL2 at 2.15 A resolution, revealing an organization similar to classical MHC class I. However, the alpha1-alpha2 domains are not tightly fixed on the alpha3-beta2m domains, indicating unusual interdomain flexibility. The groove between the two helices in the alpha1-alpha2 domains is too narrow to permit ligand binding. Notably, an unusual basic patch on the alpha3 domain is involved in the binding to heparan sulfate which is essential for MILL2 interactions with fibroblasts. These findings suggest that MILL2 has a unique structural architecture and physiological role, with binding to heparan sulfate proteoglycans on fibroblasts possibly regulating cellular recruitment in biological events.

Structure of MHC class I-like MILL2 reveals heparan-sulfate binding and interdomain flexibility.,Kajikawa M, Ose T, Fukunaga Y, Okabe Y, Matsumoto N, Yonezawa K, Shimizu N, Kollnberger S, Kasahara M, Maenaka K Nat Commun. 2018 Oct 18;9(1):4330. doi: 10.1038/s41467-018-06797-8. PMID:30337538^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.