Crystal structure of the dimeric unswapped form of bovine seminal ribonuclease.
Bovine seminal ribonuclease is a unique case of protein dimorphism, since it exists in two dimeric forms, with different biological and kinetic behavior, which interconvert into one another through three-dimensional swapping. Here we report the crystal structure, at 2.2 A resolution, of the unswapped form of bovine seminal ribonuclease. Besides completing the structural definition of bovine seminal ribonuclease conformational dimorphism, this study provides the structural basis to explain the dependence of the enzyme cooperative effects on its swapping state.
Berisio
R
R
Istituto di Biostrutture e Bioimmagini, CNR, Via Mezzocannone 6, 80134 Naples, Italy.
Sica
F
F
De Lorenzo
C
C
Di Fiore
A
A
Piccoli
R
R
Zagari
A
A
Mazzarella
L
L
D000818:Animals; D002417:Cattle; D003460:Crystallization; D018360:Crystallography, X-Ray; D019281:Dimerization; D008297:Male; D008958:Models, Molecular; D015394:Molecular Structure; D011487:Protein Conformation; D020033:Protein Isoforms / Q000737:chemistry; D020836:Protein Structure, Quaternary; D021122:Protein Subunits / Q000737:chemistry; D012260:Ribonucleases / Q000737:chemistry*; D012661:Semen / Q000201:enzymology*
D020033:Protein Isoforms; D021122:Protein Subunits; D012260:Ribonucleases