Journal
JOURNAL OF BIOLOGICAL CHEMISTRY
Volume 276, Issue 15, Pages 12024-12029Publisher
AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC
DOI: 10.1074/jbc.M010856200
Keywords
-
Categories
Ask authors/readers for more resources
alphaB-crystallin, a member of the small heat-shock protein family and a major eye lens protein, is a high molecular mass assembly and can act as a molecular chaperone. We report a synchrotron radiation x-ray solution scattering study of a truncation mutant from the human alphaB-crystallin (alpha B57-151), a dimeric protein that comprises the alpha -crystallin domain of the alphaB-crystallin and retains a significant chaperone-like activity. According to the sequence analysis (more than 23% identity), the monomeric fold of the alpha -crystallin domain should be close to that of the small heat-shock protein from Methanococcus jannaschii (MjHSP16.5). The theoretical scattering pattern computed from the crystallographic model of the dimeric MjHSP16.5 deviates significantly from the experimental scattering by the alpha -crystallin domain, pointing to different quaternary structures of the two proteins. A rigid body modeling against the solution scattering data yields a model of the alpha -crystallin domain revealing a new dimerization interface. The latter consists of a strand-turn-strand motif contributed by each of the monomers, which form a four-stranded, antiparallel, intersubunit composite beta -sheet. This model agrees with the recent spin labeling results and suggests that the alphaB-crystallin is composed by flexible building units with an extended surface area. This flexibility may be important for biological activity and for the formation of alphaB-crystallin complexes of variable sizes and compositions.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available