| RESTRAINED MOLECULAR DYNAMICS, DISTANCE GEOMETRY | RESTRAINED MOLECULAR DYNAMICS CALCULATIONS WERE DONE ON IDEALIZED A'- AND B-FORM STARTING STRUCTURES. ONLY THE TRIPLEX REGION AND THE FIRST AND LAST RESIDUES OF EACH OF THE TWO LOOPS IN THE SEQUENCE WERE CONSIDERED. THE REFINEMENT WAS CONDUCTED IN TWO STAGES. IN THE FIRST STAGE, SIX STRUCTURES WERE CALCULATED (THREE FROM EACH STARTING STRUCTURE) USING DISTANCE RESTRAINTS. IN THE SECOND STAGE, TWO OF THE SIX STRUCTURES WERE REFINED DIRECTLY AGAINST PRIMARY NOE DATA. THE R(1/6) VALUE WAS USED TO MONITOR THE REFINEMENT DURING THIS STAGE. THE FINAL R(1/6) VALUES FOR THE TWO AVERAGED MINIMIZED STRUCTURES WERE 0.04 AND 0.045. THE SUMMATION RUNS THROUGH ALL OBSERVED, QUANTIFIABLE CROSSPEAK INTENSITIES IN NOESY SPECTRA RECORDED AT MIXING TIMES OF 40, 90 AND 150 MS. RMSD BOND DISTANCES 0.016 ANGSTROMS RMSD BOND ANGLES 3.96 DEGREES RMS DEVIATIONS FROM IDEALIZED GEOMETRY FOR THE TWO AVERAGED MINIMIZED STRUCTURES ARE AS FOLLOWS: <RM-A> <RM-B> BOND (ANGSTROMS) 0.016 0.018 ANGLES (DEGREES) 3.959 4.212 IMPROPERS (DEGREES) 0.433 0.472 | X-PLOR |
