1H6K

nuclear Cap Binding Complex

Summary for 1H6K

• Entry DOI: 10.2210/pdb1h6k/pdb
• Descriptor: CBP80, 20 KDA NUCLEAR CAP BINDING PROTEIN (3 entities in total)
• Functional Keywords: m7g cap, cap-binding-complex, rnp domain, mif4g domain, rna maturation, rna export, nuclear protein
• Biological source: HOMO SAPIENS (HUMAN); More
• Total number of polymer chains: 6
• Total formula weight: 298334.74

Authors

Mazza, C.,Ohno, M.,Segref, A.,Mattaj, I.W.,Cusack, S. (deposition date: 2001-06-18, release date: 2001-09-13, Last modification date: 2024-05-08)

Primary citation

Mazza, C.,Ohno, M.,Segref, A.,Mattaj, I.W.,Cusack, S.
Crystal Structure of the Human Nuclear CAP Binding Complex
Mol.Cell, 8:383-, 2001

PubMed Abstract: The heterodimeric nuclear cap binding complex (CBC) binds to 5'-capped polymerase II transcripts. It enhances the efficiency of several mRNA maturation steps and is essential for U snRNA nuclear export in multicellular eukaryotes. The 2A crystal structure of human CBC shows that the large subunit, CBP80, comprises three domains, each containing consecutive helical hairpins and resembling the so-called MIF4G domain found in several other proteins involved in RNA metabolism. The small subunit, CPB20, has an RNP fold and associates with the second and third domains of CBP80. Site-directed mutagenesis revealed 4 residues of CBP20 which are critical for cap binding. A model for cap binding is proposed based on these results and the known mode of binding of RNA to RNP domains.

PubMed: 11545740
DOI: 10.1016/S1097-2765(01)00299-4

Experimental method

X-RAY DIFFRACTION (2 Å)