Summary information and primary citation
- PDB-id
-
4lj0;
DSSR-derived features in text and
JSON formats
- Class
- RNA binding protein
- Method
- X-ray (2.15 Å)
- Summary
- Nab2 zn fingers complexed with polyadenosine
- Reference
-
Kuhlmann SI, Valkov E, Stewart M (2014): "Structural
basis for the molecular recognition of polyadenosine RNA
by Nab2 Zn fingers." Nucleic Acids Res.,
42, 672-680. doi: 10.1093/nar/gkt876.
- Abstract
- The yeast poly(A) RNA binding protein, Nab2,
facilitates poly(A) tail length regulation together with
targeting transcripts to nuclear pores and their export to
the cytoplasm. Nab2 binds polyadenosine RNA primarily
through a tandem repeat of CCCH Zn fingers. We report here
the 2.15 Å resolution crystal structure of Zn fingers 3-5
of Chaetomium thermophilum Nab2 bound to polyadenosine RNA
and establish the structural basis for the molecular
recognition of adenosine ribonucleotides. Zn fingers 3 and
5 each bind two adenines, whereas finger 4 binds only one.
In each case, the purine ring binds in a surface groove,
where it stacks against an aromatic side chain, with
specificity being provided by a novel pattern of H-bonds,
most commonly between purine N6 and a Zn-coordinated
cysteine supplemented by H-bonds between purine N7 and
backbone amides. Residues critical for adenine binding are
conserved between species and provide a code that allows
prediction of finger-binding stoichiometry based on their
sequence. Moreover, these results indicate that, in
addition to poly(A) tails, Nab2 can also recognize sequence
motifs elsewhere in transcripts in which adenosines are
placed at key positions, consistent with its function in
mRNP organization and compaction as well as poly(A) tail
length regulation.