11BG

A POTENTIAL ALLOSTERIC SUBSITE GENERATED BY DOMAIN SWAPPING IN BOVINE SEMINAL RIBONUCLEASE

11BG の概要

• エントリーDOI: 10.2210/pdb11bg/pdb
• 分子名称: PROTEIN (BOVINE SEMINAL RIBONUCLEASE), SULFATE ION, URIDYLYL-2'-5'-PHOSPHO-GUANOSINE, ... (4 entities in total)
• 機能のキーワード: hydrolase, phosphoric diester, rna
• 由来する生物種: Bos taurus (cattle)
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 30391.41

構造登録者

Vitagliano, L.,Adinolfi, S.,Sica, F.,Merlino, A.,Zagari, A.,Mazzarella, L. (登録日: 1999-03-11, 公開日: 1999-11-05, 最終更新日: 2024-11-06)

主引用文献

Vitagliano, L.,Adinolfi, S.,Sica, F.,Merlino, A.,Zagari, A.,Mazzarella, L.
A potential allosteric subsite generated by domain swapping in bovine seminal ribonuclease.
J.Mol.Biol., 293:569-577, 1999

PubMed Abstract: Bovine seminal ribonuclease (BS-RNase) is a peculiar member of the pancreatic-like ribonuclease superfamily endowed with unique biological functions. It has been shown that native BS-RNase is a mixture of two distinct dimeric forms. The most abundant form is characterised by the swapping of the N-terminal helix. Kinetic studies have shown that this dimer is allosterically regulated, whereas the minor component, in which no swapping occurs, exhibits typical Michaelian kinetics. In order to correlate the catalytic properties with the structural features of BS-RNase, we have determined the crystal structure of the BS-RNase swapping dimer complexed with uridylyl(2'-5')guanosine. The structure of the complex was refined to an R value of 0.189 at 1.9 A resolution. Surprisingly, the enzyme binds four dinucleotide molecules, all in a non-productive way. In the two active sites, the guanine base is located in the subsite that is specific for pyrimidines. This unusual binding has been observed also in complexes of RNase A with guanine-containing nucleotides (retro-binding). One of the two additional dinucleotide molecules bound to the enzyme is located on the surface of the protein in a pocket generated by crystal packing; the second was found in a cavity at the interface between the two subunits of the swapping dimer. There are indications that the interface site plays a role in the allosteric regulation exhibited by BS-RNase. This finding suggests that domain swapping may not merely be a mechanism that proteins adopt for the transition from a monomeric to oligomeric state but can be used to achieve modulations in catalytic function.

PubMed: 10543951
DOI: 10.1006/jmbi.1999.3158

実験手法

X-RAY DIFFRACTION (1.9 Å)