1iqt
From Proteopedia
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Solution structure of the C-terminal RNA-binding domain of heterogeneous nuclear ribonucleoprotein D0 (AUF1)
Overview
Heterogeneous nuclear ribonucleoprotein (hnRNP) D0 has two, ribonucleoprotein (RNP) -type RNA-binding domains (RBDs), each of which, can specifically bind to the UUAG-sequence. hnRNP D0 also binds, specifically to single-stranded d(TTAGGG)(n), the human telomeric DNA, repeat. We have already reported the structure and interactions with RNA, of the N-terminal RBD (RBD1). Here, the structure of the C-terminal RBD, (RBD2) determined by NMR is presented. It folds into a compact alpha beta, structure comprising an antiparallel beta-sheet packed against two, alpha-helices, which is characteristic of RNP-type RBDs. In addition to, the four beta-strands commonly found in RNP-type RBDs, an extra, beta-strand, termed beta 4(-), was found just before the fourth, beta-strand, yielding a five-stranded beta-sheet. Candidate residues of, RBD2 involved in the interactions with RNA were identified by chemical, shift perturbation analysis. Perturbation was detected on the beta-sheet, side, not on the opposite alpha-helix side, as observed for RBD1. It is, notable that the beta 4(-) to beta 4 region of RBD2 is involved in the, interactions in contrast to the case of RBD1. The chemical shift, perturbation analysis also showed that RBD2 interacts with DNA in, essentially the same way as with RNA. Changes in the backbone dynamics, upon complex formation with DNA were examined by means of model free, analysis of relaxation data. In free RBD2, the beta 4(-) to beta 4 region, exhibits slow conformational exchange on the milli- to microsecond time, scale. The exchange is quenched upon complex formation. The flexibility of, free RBD2 may be utilized in the recognition process by allowing different, conformational states to be accessed and facilitating induced fit., Additionally, faster flexibility on the nano- to picosecond time scale was, observed for loop 3 located between beta 2 and beta 3 in free RBD2, which, is retained by the complex as well.
About this Structure
1IQT is a Single protein structure of sequence from Homo sapiens. Full crystallographic information is available from OCA.
Reference
Structure of the C-terminal RNA-binding domain of hnRNP D0 (AUF1), its interactions with RNA and DNA, and change in backbone dynamics upon complex formation with DNA., Katahira M, Miyanoiri Y, Enokizono Y, Matsuda G, Nagata T, Ishikawa F, Uesugi S, J Mol Biol. 2001 Aug 31;311(5):973-88. PMID:11531333
Page seeded by OCA on Mon Nov 12 17:33:37 2007
