please do # The following script load a protein, # alters the OH coordinate of TYR29 # and performs an energy minimization # on the modified residue. open from "net" "1CRN"; $X = select in 0 num 29; $A = get coord " OH " of $X; $T = <0.2,-0.2,0.0>; $i = 0; do { set coord " OH " of $X to ($A + (float)$i*$T); redraw; pause 0.25; $i++; } while ($i<10); $DIST = dist( get coord " OH " of $X, get coord " CZ " of $X ); print "Distance OH - CZ is " + (string)$DIST; $E0 = compute in "1crn" energy; $E1 = minimize $X of "1crn" with 40 cycles; $DIST = dist( get coord " OH " of $X, get coord " CZ " of $X ); print "Energy before " + (string)$E0 + " after " + (string)$E1 + ". Distance OH - CZ is now " + (string)$DIST; thank you