1h2v
From Proteopedia
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STRUCTURE OF THE HUMAN NUCLEAR CAP-BINDING-COMPLEX (CBC)
Overview
The heterodimeric nuclear cap-binding complex (CBC) binds to the 5' cap, structure of RNAs in the nucleus and plays a central role in their diverse, maturation steps. We describe the crystal structure at 2.1 A resolution of, human CBC bound to an m(7)GpppG cap analogue. Comparison with the, structure of uncomplexed CBC shows that cap binding induces co-operative, folding around the dinucleotide of some 50 residues from the N- and, C-terminal extensions to the central RNP domain of the small subunit, CBP20. The cap-bound conformation of CBP20 is stabilized by an intricate, network of interactions both to the ligand and within the subunit, as well, as new interactions of the CBP20 N-terminal tail with the large subunit, CBP80. Although the structure is very different from that of other known, cap-binding proteins, such as the cytoplasmic cap-binding protein eIF4E, specificity for the methylated guanosine again is achieved by sandwiching, the base between two aromatic residues, in this case two conserved, tyrosines. Implications for the transfer of capped mRNAs to eIF4E, required for translation initiation, are discussed.
About this Structure
1H2V is a Protein complex structure of sequences from Homo sapiens. Full crystallographic information is available from OCA.
Reference
Large-scale induced fit recognition of an m(7)GpppG cap analogue by the human nuclear cap-binding complex., Mazza C, Segref A, Mattaj IW, Cusack S, EMBO J. 2002 Oct 15;21(20):5548-57. PMID:12374755
Page seeded by OCA on Fri Feb 15 15:55:10 2008
