[NMR paper] Heteronuclear NMR studies of E. coli translation initiation factor IF3. Evidence that

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Heteronuclear NMR studies of E. coli translation initiation factor IF3. Evidence that the inter-domain region is disordered in solution.

Related Articles Heteronuclear NMR studies of E. coli translation initiation factor IF3. Evidence that the inter-domain region is disordered in solution.

J Mol Biol. 1997 Feb 14;266(1):15-22

Authors: Moreau M, de Cock E, Fortier PL, Garcia C, Albaret C, Blanquet S, Lallemand JY, Dardel F

Initiation factor IF3 from Escherichia coli plays a critical role in the selection of the correct initiation codon. This protein is composed of two domains, connected by a lysin-rich hydrophilic linker. The conformation of native IF3 was investigated by heteronuclear NMR spectroscopy. The two domains are independent and show little or no interaction. Heteronuclear relaxation studies of a sample selectively labelled on lysine residues demonstrates that the inter-domain linker is highly flexible, exhibiting increased 15N T2 values and negative 1H[15N] nuclear Overhause effects over a length of at least eight residues. Analysis of the rotational correlation times further shows that the motions of the two domains are most likely uncorrelated. The inter-domain linker thus displays almost totally unrestricted motions. Accordingly, the amide protons in the central region are shown to be in fast exchange with water. Such a high degree of flexibility of the inter-domain linker might be required for IF3 domains to interact with distant regions of the ribosome.

PMID: 9054966 [PubMed - indexed for MEDLINE]



Source: PubMed