1N3Z

Crystal structure of the [S-carboxyamidomethyl-Cys31, S-carboxyamidomethyl-Cys32] monomeric derivative of the bovine seminal ribonuclease in the liganded state

1N3Z の概要

• エントリーDOI: 10.2210/pdb1n3z/pdb
• 関連するPDBエントリー: 11BA 1BSR 4RSK
• 分子名称: Ribonuclease, seminal, 3'-URIDINEMONOPHOSPHATE, ADENOSINE, ... (4 entities in total)
• 機能のキーワード: protein-nucleotide complex, 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: 1
• 化学式量合計: 14338.16

構造登録者

Sica, F.,Di Fiore, A.,Zagari, A.,Mazzarella, L. (登録日: 2002-10-30, 公開日: 2003-08-26, 最終更新日: 2025-03-26)

主引用文献

Sica, F.,Di Fiore, A.,Zagari, A.,Mazzarella, L.
The unswapped chain of bovine seminal ribonuclease: Crystal structure of the free and liganded monomeric derivative
Proteins, 52:263-271, 2003

PubMed Abstract: Bovine seminal ribonuclease, a homodimeric enzyme joined covalently by two interchain disulphide bonds, is an equilibrium mixture of two conformational isomers, MxM and M=M. The major form, MxM, whose crystal structure has been previously determined at 1.9 A resolution, presents the swapping of the N-terminal segments (residues 1-15) and composite active sites formed by residues of different chains. The three-dimensional domain swapping does not occur in the M=M form. The different fold of each N-terminal tail is directed by the hinge loop (residue 16-22) connecting the swapping domain to the body of the protein. Reduction and alkylation of interchain disulphide bridges produce a monomeric derivative and a noncovalent swapped dimer, which are both active. The free and nucleotide-bound forms of the monomer have been crystallized at an alkaline pH and refined at 1.45 and 1.65 A resolution, respectively. In both cases, the N-terminal fragment is folded on the main body of the protein to produce an intact active site and a chain architecture very similar to that of bovine pancreatic ribonuclease. In this new fold of the seminal chain, the hinge loop is disordered. Despite the difference between the tertiary structure of the monomer and that of the chains in the MxM form, the active sites of the two enzymes are virtually indistinguishable. Furthermore, the structure of the liganded enzyme represents the first example of a ribonuclease complex studied at an alkaline pH and provides new information on the binding of a nucleotide when the catalytic histidines are deprotonated.

PubMed: 12833549
DOI: 10.1002/prot.10407

実験手法

X-RAY DIFFRACTION (1.65 Å)