Structure, stability, and function of hDim1 investigated by NMR, circular dichroism, and mutational analysis.


The 142 amino acid Dim1p protein is a component of the U4/U6.U5 tri-snRNP complex required for pre-mRNA splicing and interacts with multiple splicing-associated proteins. To gain further insight into the structural basis of its function, we determined the solution structure of the reduced form of the dominant negative human hDim1 (hDim1(1)(-)(128)) using multidimensional NMR spectroscopy. This dominant negative hDim1 assumes a thioredoxin-like fold, confirming previous NMR and crystallographic results. However, in contrast to a recent crystal structure, the NMR solution structure for the reduced form of hDim1(1)(-)(128) presented here, along with thermodynamic data, indicates that the presence of a disulfide bond between Cys38 and Cys79 is structurally and functionally unimportant. Comparison of the truncated hDim1(1)(-)(128) with the full-length protein, using NMR and circular dichroism spectroscopy, indicates that the 14 C-terminal residues can undergo a local unfolding transition and assume alternative conformations, which appear to play a functional role. Other residues essential for hDim1 function are identified by using mutational and genetic approaches. The residues thus identified are not identical with those previously shown to govern Dim1 interaction with defined protein partners. Study holds ProTherm entries: 16576, 16577, 16578 Extra Details: oxidized tri-snRNP complex; thioredoxin-like fold; disulfide bond; functional role

Submission Details

ID: eSXgcEt63

Submitter: Connie Wang

Submission Date: April 24, 2018, 8:48 p.m.

Version: 1

Publication Details
Zhang YZ;Cheng H;Gould KL;Golemis EA;Roder H,Biochemistry (2003) Structure, stability, and function of hDim1 investigated by NMR, circular dichroism, and mutational analysis. PMID:12911302
Additional Information

Structure view and single mutant data analysis

Study data

No weblogo for data of varying length.
Colors: D E R H K S T N Q A V I L M F Y W C G P

Data Distribution

Studies with similar sequences (approximate matches)

Correlation with other assays (exact sequence matches)

Relevant PDB Entries

Structure ID Release Date Resolution Structure Title
1PQN 2003-06-18T00:00:00+0000 0 dominant negative human hDim1 (hDim1 1-128)
1QGV 1999-05-06T00:00:00+0000 1.4 HUMAN SPLICEOSOMAL PROTEIN U5-15KD
1SYX 2004-04-02T00:00:00+0000 2.35 The crystal structure of a binary U5 snRNP complex
3JCR 2016-01-21T00:00:00+0000 7.0 3D structure determination of the human*U4/U6.U5* tri-snRNP complex
4BWQ 2013-07-04T00:00:00+0000 2.1 Crystal structure of U5-15kD in a complex with PQBP1
4BWS 2013-07-04T00:00:00+0000 2.5 Crystal structure of the heterotrimer of PQBP1, U5-15kD and U5-52kD.
4CDO 2013-11-05T00:00:00+0000 2.5 Crystal structure of PQBP1 bound to spliceosomal U5-15kD
5O9Z 2017-06-20T00:00:00+0000 4.5 Cryo-EM structure of a pre-catalytic human spliceosome primed for activation (B complex)
6AH0 2018-08-15T00:00:00+0000 5.7 The Cryo-EM Structure of the Precusor of Human Pre-catalytic Spliceosome (pre-B complex)
6AHD 2018-08-17T00:00:00+0000 3.8 The Cryo-EM Structure of Human Pre-catalytic Spliceosome (B complex) at 3.8 angstrom resolution

Relevant UniProtKB Entries

Percent Identity Matching Chains Protein Accession Entry Name
100.0 Thioredoxin-like protein 4A P83877 TXN4A_MOUSE
100.0 Thioredoxin-like protein 4A P83876 TXN4A_HUMAN