1AMM

1.2 ANGSTROM STRUCTURE OF GAMMA-B CRYSTALLIN AT 150K

Summary for 1AMM

• Entry DOI: 10.2210/pdb1amm/pdb
• Descriptor: GAMMA B-CRYSTALLIN (2 entities in total)
• Functional Keywords: eye lens protein, crystallin
• Biological source: Bos taurus (cattle)
• Total number of polymer chains: 1
• Total formula weight: 20992.56

Authors

Kumaraswamy, V.S.,Lindley, P.F.,Slingsby, C.,Glover, I.D. (deposition date: 1996-03-20, release date: 1996-11-08, Last modification date: 2024-02-07)

Primary citation

Kumaraswamy, V.S.,Lindley, P.F.,Slingsby, C.,Glover, I.D.
An eye lens protein-water structure: 1.2 A resolution structure of gammaB-crystallin at 150 K.
Acta Crystallogr.,Sect.D, 52:611-622, 1996

PubMed Abstract: gammabeta-crystallin is a structural protein of the eye lens with a role in the maintenance of an even distribution of protein and water over distances around the wavelength of light, preserving lens transparency. The structure of the 174-residue bovine protein has already been determined at room temperature to 1.47 A resolution. By flash freezing the protein crystals, data have now been collected to a nominal resolution limit of 1.2 A as radiation damage was essentially eliminated. The protein-water model has been refined against this data using the program RESTRAIN converging to an R factor of 18.5% with all data. Atomic positions are clearly indicated in the electron-density maps. Discrete bimodal disorder has been visualized for a few side chains. Out of a total of 498 water molecules present in the crystal asymmetric unit, 394 have been modelled and refined at unit occupancy. The solvent structure is extremely well ordered with an average B value of 23.4 A(2). Partially occupied sites have been identified where disorder in the protein induces concomitant disorder in the local solvent structure. The solvent structure covers 97% of the solvent-exposed surface of the protein in the crystal. 126 water molecules are distributed in second and higher hydration shells. There are networks of hydrogen-bonded solvent extending up to 64 molecules in a network, comprising trimers and tetramers as well as five- and six-membered water-ring structures. The hydration of the protein surface is dominated by arginine and aspartate side chains. Extensive cages of highly ordered solvent molecules are also observed around exposed non-polar groups.

PubMed: 15299624
DOI: 10.1107/S0907444995014302

Experimental method

X-RAY DIFFRACTION (1.2 Å)