 |
PDBsum entry 2c4z
|
|
|
|
References listed in PDB file
|
 |
|
Key reference
|
|
|
Title
|
|
Structural basis of pyrimidine specificity in the ms2 RNA hairpin-Coat-Protein complex.
|
|
|
Authors
|
|
E.Grahn,
T.Moss,
C.Helgstrand,
K.Fridborg,
M.Sundaram,
K.Tars,
H.Lago,
N.J.Stonehouse,
D.R.Davis,
P.G.Stockley,
L.Liljas.
|
|
|
Ref.
|
|
Rna, 2001,
7,
1616-1627.
|
|
|
PubMed id
|
|
|
|
|
|
Abstract
|
|
|
We have determined the X-ray structures of six MS2 RNA hairpin-coat-protein
complexes having five different substitutions at the hairpin loop base -5. This
is a uracil in the wild-type hairpin and contacts the coat protein both by
stacking on to a tyrosine side chain and by hydrogen bonding to an asparagine
side chain. The RNA consensus sequence derived from coat protein binding studies
with natural sequence variants suggested that the -5 base needs to be a
pyrimidine for strong binding. The five -5 substituents used in this study were
5-bromouracil, pyrimidin-2-one, 2-thiouracil, adenine, and guanine. The
structure of the 5-bromouracil complex was determined to 2.2 A resolution, which
is the highest to date for any MS2 RNA-protein complex. All the complexes
presented here show very similar conformations, despite variation in affinity in
solution. The results suggest that the stacking of the -5 base on to the
tyrosine side chain is the most important driving force for complex formation. A
number of hydrogen bonds that are present in the wild-type complex are not
crucial for binding, as they are missing in one or more of the complexes. The
results also reveal the flexibility of this RNA-protein interface, with respect
to functional group variation, and may be generally applicable to other
RNA-protein complexes.
|
|
|
|
|
|
|
