1XBS

Crystal structure of human dim2: a dim1-like protein

1XBS の概要

• エントリーDOI: 10.2210/pdb1xbs/pdb
• 分子名称: Dim1-like protein (2 entities in total)
• 機能のキーワード: spliceosomal protein, cell cycle, thioredoxin, snrnp, transcription
• 由来する生物種: Homo sapiens (human)
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 17034.61

構造登録者

Simeoni, F.,Arvai, A.,Hopfner, K.-P.,Bello, P.,Gondeau, C.,Heitz, F.,Tainer, J.,Divita, G. (登録日: 2004-08-31, 公開日: 2005-08-30, 最終更新日: 2024-02-14)

主引用文献

Simeoni, F.,Arvai, A.,Bello, P.,Gondeau, C.,Hopfner, K.-P.,Neyroz, P.,Heitz, F.,Tainer, J.,Divita, G.
Biochemical Characterization and Crystal Structure of a Dim1 Family Associated Protein: Dim2
Biochemistry, 44:11997-12008, 2005

PubMed Abstract: The U4/U6*U5 tri-snRNP complex is the catalytic core of the pre-mRNA splicing machinery. The thioredoxin-like protein hDim1 (U5-15 kDa) constitutes an essential component of the U5 particle, and its functions have been reported to be highly conserved throughout evolution. Recently, the Dim1-like protein (DLP) family has been extended to other proteins harboring similar sequence motifs. Here we report the biochemical characterization and crystallographic structure of a 149 amino acid protein, hDim2, which shares 38% sequence identity with hDim1. The crystallographic structure of hDim2 solved at 2.5 A reveals a classical thioredoxin-fold structure. However, despite the similarity in the thioredoxin fold, hDim2 differs from hDim1 in many significant features. The structure of hDim2 contains an extra alpha helix (alpha3) and a beta strand (beta5), which stabilize the protein, suggesting that they may be involved in interactions with hDim2-specific partners. The stability and thermodynamic parameters of hDim2 were evaluated by combining circular dichroism and fluorescence spectroscopy together with chromatographic and cross-linking approaches. We have demonstrated that, in contrast to hDim1, hDim2 forms stable homodimers. The dimer interface is essentially stabilized by electrostatic interactions and involves tyrosine residues located in the alpha3 helix. Structural analysis reveals that hDim2 lacks some of the essential structural motifs and residues that are required for the biological activity and interactive properties of hDim1. Therefore, on the basis of structural investigations we suggest that, in higher eukaryotes, although both hDim1 and hDim2 are involved in pre-mRNA splicing, the two proteins are likely to participate in different multisubunit complexes and biological processes.

PubMed: 16142897
DOI: 10.1021/bi050427o

実験手法

X-RAY DIFFRACTION (2.5 Å)