Human ?B2-Crystallin Forms a Face-en-Face Dimer in Solution: An Integrated NMR and SAXS Study.
 

Human ?B2-Crystallin Forms a Face-en-Face Dimer in Solution: An Integrated NMR and SAXS Study.

Related Articles Human ?B2-Crystallin Forms a Face-en-Face Dimer in Solution: An Integrated NMR and SAXS Study.

Structure. 2017 Feb 16;:

Authors: Xi Z, Whitley MJ, Gronenborn AM

Abstract
??-Crystallins are long-lived eye lens proteins that are crucial for lens transparency and refractive power. Each ??-crystallin comprises two homologous domains, which are connected by a short linker. ?-Crystallins are monomeric, while ?-crystallins crystallize as dimers and multimers. In the crystal, human ?B2-crystallin is a domain-swapped dimer while the N-terminally truncated ?B1-crystallin forms a face-en-face dimer. Combining and integrating data from multi-angle light scattering, nuclear magnetic resonance, and small-angle X-ray scattering of full-length and terminally truncated human ?B2-crystallin in solution, we show that both these ?B2-crystallin proteins are dimeric, possess C2 symmetry, and are more compact than domain-swapped dimers. Importantly, no inter-molecular paramagnetic relaxation enhancement effects compatible with domain swapping were detected. Our collective experimental results unambiguously demonstrate that, in solution, human ?B2-crystallin is not domain swapped and exhibits a face-en-face dimer structure similar to the crystal structure of truncated ?B1-crystallin.


PMID: 28238532 [PubMed - as supplied by publisher]



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