The rate-limiting step for the folding of the helix-turn helix (HTH) protein, Z34C, involves beta-turn region (DPNL23)-D-20. This reverse turn has been observed to be part of the transition state in the folding process for Z34C, influencing its folding rates. Molecular dynamics simulations were performed on this turn peptide and its two mutants, D20A and P21A, to study turn formation using GROMO-S54A7 force field. We find that this region has a turn propensity of its own, and the highest turn propensity is observed for the wild-type, which correlates well with available experimental results. We also find that a slight unfavorable change in Delta G (turn) (folding) causes a drastic change in the folding rates of HTH motif and a mechanistic interpretation is given. Implications of these observations for the folding of the HTH protein Z34C are discussed.