3L1F

Bovine AlphaA crystallin

Summary for 3L1F

• Entry DOI: 10.2210/pdb3l1f/pdb
• Descriptor: Alpha-crystallin A chain, (4S)-2-METHYL-2,4-PENTANEDIOL (3 entities in total)
• Functional Keywords: lens transparency, polydispersity, protein aggregation, crystallin, eye lens protein, chaperone
• Biological source: Bos taurus (bovine)
• Cellular location: Cytoplasm : P02470
• Total number of polymer chains: 1
• Total formula weight: 11777.09

Authors

Laganowsky, A.,Sawaya, M.R.,Cascio, D.,Eisenberg, D. (deposition date: 2009-12-11, release date: 2010-05-12, Last modification date: 2024-02-21)

Primary citation

Laganowsky, A.,Benesch, J.L.,Landau, M.,Ding, L.,Sawaya, M.R.,Cascio, D.,Huang, Q.,Robinson, C.V.,Horwitz, J.,Eisenberg, D.
Crystal structures of truncated alphaA and alphaB crystallins reveal structural mechanisms of polydispersity important for eye lens function.
Protein Sci., 19:1031-1043, 2010

PubMed Abstract: Small heat shock proteins alphaA and alphaB crystallin form highly polydisperse oligomers that frustrate protein aggregation, crystallization, and amyloid formation. Here, we present the crystal structures of truncated forms of bovine alphaA crystallin (AAC(59-163)) and human alphaB crystallin (ABC(68-162)), both containing the C-terminal extension that functions in chaperone action and oligomeric assembly. In both structures, the C-terminal extensions swap into neighboring molecules, creating runaway domain swaps. This interface, termed DS, enables crystallin polydispersity because the C-terminal extension is palindromic and thereby allows the formation of equivalent residue interactions in both directions. That is, we observe that the extension binds in opposite directions at the DS interfaces of AAC(59-163) and ABC(68-162). A second dimeric interface, termed AP, also enables polydispersity by forming an antiparallel beta sheet with three distinct registration shifts. These two polymorphic interfaces enforce polydispersity of alpha crystallin. This evolved polydispersity suggests molecular mechanisms for chaperone action and for prevention of crystallization, both necessary for transparency of eye lenses.

PubMed: 20440841
DOI: 10.1002/pro.380

Experimental method

X-RAY DIFFRACTION (1.53 Å)