3LOW: Crystal structure of Beta 2 Microglobulin domain-swapped dimer

beta(2)-microglobulin (beta(2)m) is the light chain of the type I major histocompatibility complex. It deposits as amyloid fibrils within joints during long-term hemodialysis treatment. Despite the devastating effects of dialysis-related amyloidosis, full understanding of how fibrils form from soluble beta(2)m remains elusive. Here we show that beta(2)m can oligomerize and fibrillize via three-dimensional domain swapping. Isolating a covalently bound, domain-swapped dimer from beta(2)m oligomers on the pathway to fibrils, we were able to determine its crystal structure. The hinge loop that connects the swapped domain to the core domain includes the fibrillizing segment LSFSKD, whose atomic structure we also determined. The LSFSKD structure reveals a class 5 steric zipper, akin to other amyloid spines. The structures of the dimer and the zipper spine fit well into an atomic model for this fibrillar form of beta(2)m, which assembles slowly under physiological conditions.
PDB ID: 3LOWDownload
MMDB ID: 87154
PDB Deposition Date: 2010/2/4
Updated in MMDB: 2010/12
Experimental Method:
x-ray diffraction
Resolution: 2.3  Å
Source Organism:
Similar Structures:
Biological Unit for 3LOW: dimeric; determined by author and by software (PISA)
Molecular Components in 3LOW
Label Count Molecule
Proteins (2 molecules)
Beta-2-microglobulin(Gene symbol: B2M)
Molecule annotation
Chemicals (3 molecules)
* Click molecule labels to explore molecular sequence information.

Citing MMDB