3ENU

Crystal structure of Nitrollin, a betagamma-crystallin from Nitrosospira multiformis

Summary for 3ENU

• Entry DOI: 10.2210/pdb3enu/pdb
• Related: 3ENT
• Descriptor: Putative uncharacterized protein (2 entities in total)
• Functional Keywords: betagamma crystallin, structural protein
• Biological source: Nitrosospira multiformis
• Total number of polymer chains: 1
• Total formula weight: 12949.71

Authors

Aravind, P.,Sankaranarayanan, R. (deposition date: 2008-09-26, release date: 2009-03-31, Last modification date: 2017-10-25)

Primary citation

Aravind, P.,Suman, S.K.,Mishra, A.,Sharma, Y.,Sankaranarayanan, R.
Three-dimensional domain swapping in nitrollin, a single-domain betagamma-crystallin from Nitrosospira multiformis, controls protein conformation and stability but not dimerization
J.Mol.Biol., 385:163-177, 2009

PubMed Abstract: The betagamma-crystallin superfamily has a well-characterized protein fold, with several members found in both prokaryotic and eukaryotic worlds. A majority of them contain two betagamma-crystallin domains. A few examples, such as ciona crystallin and spherulin 3a exist that represent the eukaryotic single-domain proteins of this superfamily. This study reports the high-resolution crystal structure of a single-domain betagamma-crystallin protein, nitrollin, from the ammonium-oxidizing soil bacterium Nitrosospira multiformis. The structure retains the characteristic betagamma-crystallin fold despite a very low sequence identity. The protein exhibits a unique case of homodimerization in betagamma-crystallins by employing its N-terminal extension to undergo three-dimensional (3D) domain swapping with its partner. Removal of the swapped strand results in partial loss of structure and stability but not dimerization per se as determined using gel filtration and equilibrium unfolding studies. Overall, nitrollin represents a distinct single-domain prokaryotic member that has evolved a specialized mode of dimerization hitherto unknown in the realm of betagamma-crystallins.

PubMed: 18976659
DOI: 10.1016/j.jmb.2008.10.035

Experimental method

X-RAY DIFFRACTION (1.86 Å)