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PDBsum entry 1d9r
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References listed in PDB file
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Key reference
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Title
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Structure and recognition of sheared tandem g X a base pairs associated with human centromere DNA sequence at atomic resolution.
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Authors
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Y.G.Gao,
H.Robinson,
R.Sanishvili,
A.Joachimiak,
A.H.Wang.
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Ref.
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Biochemistry, 1999,
38,
16452-16460.
[DOI no: ]
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PubMed id
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Abstract
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G x A mismatched base pairs are frequently found in nucleic acids. Human
centromere DNA sequences contain unusual repeating motifs, e.g. , (GAATG)n x
(CATTC)n found in the human chromosome. The purine-rich strand of this repeating
pentamer sequence forms duplex and hairpin structures with unusual stability.
The high stability of these structures is contributed by the "sheared" G x A
base pairs which present a novel recognition surface for ligands and proteins.
We have solved the crystal structure, by the multiple-wavelength anomalous
diffraction (MAD) method of d(CCGAATGAGG) in which the centromere core sequence
motif GAATG is embedded. Three crystal forms were refined to near-atomic
resolution. The structures reveal the detailed conformation of tandem G x A base
pairs whose unique hydrogen-bonding surface has interesting interactions with
bases, hydrated magnesium ions, cobalt(III)hexaammine, spermine, and water
molecules. The results are relevant in understanding the structure associated
with human centromere sequence in particular and G x A base pairs in nucleic
acids (including RNA, like ribozyme) in general.
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Headers
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