1A2W

CRYSTAL STRUCTURE OF A 3D DOMAIN-SWAPPED DIMER OF BOVINE PANCREATIC RIBONUCLEASE A

Summary for 1A2W

• Entry DOI: 10.2210/pdb1a2w/pdb
• Descriptor: RIBONUCLEASE A, CHLORIDE ION, SULFATE ION, ... (4 entities in total)
• Functional Keywords: endonuclease, ribonuclease, domain swapping, hydrolase, protein-protein interaction
• Biological source: Bos taurus (cattle)
• Cellular location: Secreted: P61823
• Total number of polymer chains: 2
• Total formula weight: 27583.62

Authors

Liu, Y.,Hart, P.J.,Schlunegger, M.P.,Eisenberg, D.S. (deposition date: 1998-01-12, release date: 1998-04-29, Last modification date: 2024-10-30)

Primary citation

Liu, Y.,Hart, P.J.,Schlunegger, M.P.,Eisenberg, D.
The crystal structure of a 3D domain-swapped dimer of RNase A at a 2.1-A resolution.
Proc.Natl.Acad.Sci.USA, 95:3437-3442, 1998

PubMed Abstract: The dimer of bovine pancreatic ribonuclease A (RNase A) discovered by Crestfield, Stein, and Moore in 1962 has been crystallized and its structure determined and refined to a 2.1-A resolution. The dimer is 3D domain-swapped. The N-terminal helix (residues 1-15) of each subunit is swapped into the major domain (residues 23-124) of the other subunit. The dimer of bull seminal ribonuclease (BS-RNase) is also known to be domain-swapped, but the relationship of the subunits within the two dimers is strikingly different. In the RNase A dimer, the 3-stranded beta sheets of the two subunits are hydrogen-bonded at their edges to form a continuous 6-stranded sheet across the dimer interface; in the BS-RNase dimer, it is instead the two helices that abut. Whereas the BS-RNase dimer has 2-fold molecular symmetry, the two subunits of the RNase A dimer are related by a rotation of approximately 160 degrees. Taken together, these structures show that intersubunit adhesion comes mainly from the swapped helical domain binding to the other subunit in the "closed interface" but that the overall architecture of the domain-swapped oligomer depends on the interactions in the second type of interface, the "open interface." The RNase A dimer crystals take up the dye Congo Red, but the structure of a Congo Red-stained crystal reveals no bound dye molecule. Dimer formation is inhibited by excess amounts of the swapped helical domain. The possible implications for amyloid formation are discussed.

PubMed: 9520384
DOI: 10.1073/pnas.95.7.3437

Experimental method

X-RAY DIFFRACTION (2.1 Å)