1d9r
From Proteopedia
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CRYSTAL STRUCTURE OF DNA SHEARED TANDEM G-A BASE PAIRS
Overview
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.
About this Structure
1D9R is a Protein complex structure of sequences from [1] with NCO as ligand. Full crystallographic information is available from OCA.
Reference
Structure and recognition of sheared tandem G x A base pairs associated with human centromere DNA sequence at atomic resolution., Gao YG, Robinson H, Sanishvili R, Joachimiak A, Wang AH, Biochemistry. 1999 Dec 14;38(50):16452-60. PMID:10600106
Page seeded by OCA on Sun Nov 25 02:50:11 2007
