1x0f
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Complex structure of the C-terminal RNA-binding domain of hnRNP D(AUF1) with telomeric DNA
OverviewOverview
Heterogeneous nuclear ribonucleoprotein D, also known as AUF1, has two, DNA/RNA-binding domains, each of which can specifically bind to, single-stranded d(TTAGGG)n, the human telomeric repeat. Here, the, structure of the C-terminal-binding domain (BD2) complexed with, single-stranded d(TTAGGG) determined by NMR is presented. The structure, has revealed that each residue of the d(TAG) segment is recognized by BD2, in a base-specific manner. The interactions deduced from the structure, have been confirmed by gel retardation experiments with mutant BD2 and, DNA. It is known that single-stranded DNA with the telomeric repeat tends, to form a quadruplex and that the quadruplex has an inhibitory effect on, telomere elongation by telomerase. This time it is revealed that BD2, unfolds the quadruplex of such DNA upon binding. Moreover, the effect of, BD2 on the elongation by telomerase was examined in vitro. These results, suggest the possible involvement of heterogeneous nuclear, ribonucleoprotein D in maintenance of the telomere 3'-overhang either, through protection of a single-stranded DNA or destabilization of the, potentially deleterious quadruplex structure for the elongation by, telomerase.
About this StructureAbout this Structure
1X0F is a Single protein structure of sequence from Homo sapiens. Full crystallographic information is available from OCA.
ReferenceReference
Structure of hnRNP D complexed with single-stranded telomere DNA and unfolding of the quadruplex by heterogeneous nuclear ribonucleoprotein D., Enokizono Y, Konishi Y, Nagata K, Ouhashi K, Uesugi S, Ishikawa F, Katahira M, J Biol Chem. 2005 May 13;280(19):18862-70. Epub 2005 Feb 24. PMID:15734733
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