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Crystal structure of truncated human βB1‐crystallin
Author(s) -
van Montfort Rob L.M.,
Bateman Orval A.,
Lubsen Nicolette H.,
Slingsby Christine
Publication year - 2003
Publication title -
protein science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.353
H-Index - 175
eISSN - 1469-896X
pISSN - 0961-8368
DOI - 10.1110/ps.03265903
Subject(s) - tetramer , dimer , crystallin , crystallography , oligomer , crystal structure , monomer , linker , lens (geology) , chemistry , biophysics , biology , optics , physics , biochemistry , enzyme , operating system , organic chemistry , computer science , polymer
Crystallins are long‐lived proteins packed inside eye lens fiber cells that are essential in maintaining the transparency and refractive power of the eye lens. Members of the two‐domain βγ‐crystallin family assemble into an array of oligomer sizes, forming intricate higher‐order networks in the lens cell. Here we describe the 1.4 Å resolution crystal structure of a truncated version of human βB1 that resembles an in vivo age‐related truncation. The structure shows that unlike its close homolog, βB2‐crystallin, the homodimer is not domain swapped, but its domains are paired intramolecularly, as in more distantly related monomeric γ‐crystallins. However, the four‐domain dimer resembles one half of the crystallographic bovine βB2 tetramer and is similar to the engineered circular permuted rat βB2. The crystal structure shows that the truncated βB1 dimer is extremely well suited to form higher‐order lattice interactions using its hydrophobic surface patches, linker regions, and sequence extensions.