THE UNUSUAL STRUCTURE OF THE HUMAN CENTROMERE (GGA)2 MOTIF: UNPAIRED GUANOSINE RESIDUES STACKED BETWEEN SHEARED G(DOT)A PAIRS
The unusual structure of the human centromere (GGA)2 motif. Unpaired guanosine residues stacked between sheared G.A pairs.
DNA (5'-D(*GP*TP*GP*GP*AP*AP*TP*GP*GP*AP*AP*C)-3')
R VALUE 0.250 FINAL RMS COORD. SHIFT 0.65 ANGSTROMS NUMBER OF ATOMS USED IN REFINEMENT. NUMBER OF PROTEIN ATOMS 0 NUMBER OF NUCLEIC ACID ATOMS 772 NUMBER OF HETEROGEN ATOMS 0 NUMBER OF SOLVENT ATOMS 0. THE DUPLEX CONTAINS UNPAIRED STAGGERED GUANOSINE RESIDUES, WHICH CO-STACK BY INTERCALATION BETWEEN SHEARED G(DOT)A AND A(DOT)G BASE-PAIRS TO FORM AN INTERESTING NEW STRUCTURAL MOTIF, THE GA-BRACKETED G-STACK. THE TGGAA REPEAT UNIT CONTAINS SIX "STEPS", FOUR OF WHICH ARE NOT WATSON-CRICK BASE-PAIRS.
DNA, DOUBLE HELIX, G-G STACKING, G:A MISMATCH, HUMAN CENTROMERE REPEAT, GA-BRACKETED G-STACK MOTIF