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This is the Settings section of the mfold settings tab.

ParameterUnitDefaultLimitsTool argument nameDescription
Temperature°C37[0,100]T

The folding temperature.

For RNA this is always the default value. For DNA it is taken from the dialog.

Ionic conditionsMNa=1[0,1.5]

NA_CONC

Ionic conditions are used to enter total monovalent (Na) and divalent (Mg) ions concentrations.

For RNA this is always the default values. For DNA it is taken from the dialog.

Mg=0MG_CONC
Percent suboptimality%5[1,100]P

The suboptimality percentage controls the free energy increment δδG for computing suboptimal foldings. Only foldings with a free energy ≤ΔG+δδG will be computed, where ΔG is the predicted minimum free energy. Normally, δδG=(P/100)|ΔG|, but it is rounded up to 1 kcal/mol or down to 12 kcal/mol if it is outside this range.

Max num of foldings
50[1,100]MAXThis is the maximum number of foldings that mfold will compute. It is better to limit the number of foldings by careful selection of the P and W parameters.
Window
0 (len≤29)
1 (30≤len≤49)
2 (50≤len≤119)
3 (120≤len≤199)
5 (200≤len≤299)
7 (300≤len≤399)
8 (400≤len≤499)
10 (500≤len≤599)
11 (600≤len≤699)
12 (700≤len≤799)
15 (800≤len≤1199)
20 (1200≤len≤1999)
25 (2000≤len)
[0,50]W

The window parameter, W, controls the number of foldings that are computed. It may be thought of as a distance parameter. The distance between 2 base pairs, ri rj and ri' rj' may be defined as max{|i-i′|, |j-j′|}. If k-1 foldings have already been predicted by mfold, the kth folding must have at least W base pairs that are at least a distance W from any of the base pairs in the first k-1 foldings. A new folding is not added to the output list unless this criterion is fulfilled. As W increases, the number of predicted foldings decreases. A smaller value of this parameter will usually result in more computed foldings that may be quite similar to one another. A larger value will result in fewer foldings that are very different from one another.

If the parameter is set to the default value, then in the calculations the real value of W will be set according to the described algorithm, based on the length of the selected region of the input sequence (see the Default column).

Max base pair distance
[1,∞]MAXBP

If the maximum distance between paired bases parameter, MAXBP, is specified, then any base pair, ri rj, in a folding must satisfy
j-i≤MAXBP for a linear sequence
or
min{j-i, len+i-j}≤MAXBP, for a circular sequence (len is the length of the selected region of the input sequence).

Thus small values of MAXBP ensure that only short range base pairs will be predicted. For example, in a sequence of 1000 nucleotides, setting MAXBP to 50 will force mfold to compute foldings involving only short range base pairs.

The default is MAXBP=∞, which means no constraint.

Display settings

Corresponds to the Extended settings section on the main tab.

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