1NU4

U1A RNA binding domain at 1.8 angstrom resolution reveals a pre-organized C-terminal helix

Summary for 1NU4

• Entry DOI: 10.2210/pdb1nu4/pdb
• Related: 1nrc 1urn
• Descriptor: U1A RNA binding domain, MAGNESIUM ION, MALONIC ACID, ... (4 entities in total)
• Functional Keywords: rna recognition motif, u1 small nuclear ribonucleoprotein, rna binding domain, rna binding protein
• Biological source: Homo sapiens (human)
• Cellular location: Nucleus: P09012
• Total number of polymer chains: 2
• Total formula weight: 23788.50

Authors

Rupert, P.B.,Xiao, H.,Ferre-D'Amare, A.R. (deposition date: 2003-01-30, release date: 2003-02-14, Last modification date: 2023-08-16)

Primary citation

Rupert, P.B.,Xiao, H.,Ferre-D'Amare, A.R.
U1A RNA-binding domain at 1.8 A resolution.
Acta Crystallogr.,Sect.D, 59:1521-1524, 2003

PubMed Abstract: The human U1A RNA-binding domain (RBD1) adopts one of the most common protein folds, the RNA-recognition motif, and is a paradigm for understanding RNA-protein interactions. A 2.8 A resolution structure of the unbound RBD1 has previously been determined [Nagai et al. (1990). Nature (London), 348, 515-520] and revealed a well defined alpha/beta core with disordered termini. Using a longer construct, a 1.8 A resolution structure of the unbound domain was determined that reveals an ordered C-terminal helix. The presence of this helix is consistent with a solution structure of the free domain [Avis et al. (1996). J. Mol. Biol. 257, 398-411]; however, in the solution structure the helix occludes the RNA-binding surface. In the present structure, the helix occupies a position similar to that seen in a 1.9 A resolution RNA-RBD1 complex structure [Oubridge et al. (1994). Nature (London), 372, 432-438]. The crystals in this study were grown from 2.2 M sodium malonate. It is possible that the high salt concentration helps to orient the C-terminal helix in the RNA-bound conformation by strengthening hydrophobic interactions between the buried face of the helix and the alpha/beta core of the protein. Alternatively, the malonate (several molecules of which are bound in the vicinity of the RNA-binding surface) may mimic RNA.

PubMed: 12876372
DOI: 10.1107/S0907444903011338

Experimental method

X-RAY DIFFRACTION (1.8 Å)