BS-RNase tetramers: an example of domain-swapped oligomers.
In the ribonuclease superfamily, dimericity is a unique feature of bovine seminal RNase (BS-RNase). In about two-thirds of native BS-RNase molecules, the two subunits interchange their N-terminal tails, thus generating domain-swapped dimers (MxM), which mostly responsible for enzyme biological activities and allostericity. Higher molecular weight BS-RNase oligomers can also be prepared [Libonati, M. (1969) Ital. J. Biochem. 18, 407-417.]. This paper reports on BS-RNase tetrameric derivatives which were isolated and enzymatically characterized. The data collected and the analysis of the crystal packing of MxM dimers suggested a structural model for tetramer assembly, in which the four subunits are enchained by multiple domain-swapping events.
Adinolfi
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S
CNR, Centro di Studio di Biocristallographia and Dipartimento di Chimica, Universita Federico II di Napoli, Italy.
Piccoli
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R
Sica
F
F
Mazzarella
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L
D001665:Binding Sites; D001704:Biopolymers; D002851:Chromatography, High Pressure Liquid; D018360:Crystallography, X-Ray; D003597:Cytosine Nucleotides / Q000378:metabolism; D019281:Dimerization; D004591:Electrophoresis, Polyacrylamide Gel; D004722:Endoribonucleases / Q000737:chemistry* / Q000378:metabolism; D008958:Models, Molecular; D008970:Molecular Weight; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D012331:RNA, Fungal / Q000378:metabolism
D001704:Biopolymers; D003597:Cytosine Nucleotides; D012331:RNA, Fungal; C019310:cifostodine; D004722:Endoribonucleases; C032523:ribonuclease SPL