1Y92

Crystal structure of the P19A/N67D Variant Of Bovine seminal Ribonuclease

1Y92 の概要

• エントリーDOI: 10.2210/pdb1y92/pdb
• 関連するPDBエントリー: 1BSR 1R5D 1y94
• 分子名称: Seminal ribonuclease (2 entities in total)
• 機能のキーワード: nuclease, hydrolase
• 由来する生物種: Bos taurus (cattle)
• 細胞内の位置: Secreted: P00669
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 27215.17

構造登録者

Picone, D.,Di Fiore, A.,Ercole, C.,Franzese, M.,Sica, F.,Tomaselli, S.,Mazzarella, L. (登録日: 2004-12-14, 公開日: 2004-12-28, 最終更新日: 2024-10-30)

主引用文献

Picone, D.,Di Fiore, A.,Ercole, C.,Franzese, M.,Sica, F.,Tomaselli, S.,Mazzarella, L.
The Role of the Hinge Loop in Domain Swapping: THE SPECIAL CASE OF BOVINE SEMINAL RIBONUCLEASE.
J.Biol.Chem., 280:13771-13778, 2005

PubMed Abstract: Bovine seminal ribonuclease (BS-RNase) is a covalent homodimeric enzyme homologous to pancreatic ribonuclease (RNase A), endowed with a number of special biological functions. It is isolated as an equilibrium mixture of swapped (MxM) and unswapped (M=M) dimers. The interchanged N termini are hinged on the main bodies through the peptide 16-22, which changes conformation in the two isomers. At variance with other proteins, domain swapping in BS-RNase involves two dimers having a similar and highly constrained quaternary association, mainly dictated by two interchain disulfide bonds. This provides the opportunity to study the intrinsic ability to swap as a function of the hinge sequence, without additional effects arising from dissociation or quaternary structure modifications. Two variants, having Pro19 or the whole sequence of the hinge replaced by the corresponding residues of RNase A, show equilibrium and kinetic parameters of the swapping similar to those of the parent protein. In comparison, the x-ray structures of MxM indicate, within a substantial constancy of the quaternary association, a greater mobility of the hinge residues. The relative insensitivity of the swapping tendency to the substitutions in the hinge region, and in particular to the replacement of Pro19 by Ala, contrasts with the results obtained for other swapped proteins and can be rationalized in terms of the unique features of the seminal enzyme. Moreover, the results indirectly lend credit to the hypothesis that the major role of Pro19 resides in directing the assembly of the non-covalent dimer, the species produced by selective reduction of the interchain disulfides and considered responsible for the special biological functions of BS-RNase.

PubMed: 15647261
DOI: 10.1074/jbc.M413157200

実験手法

X-RAY DIFFRACTION (2.2 Å)