Welcome to the Fold Web Server

The Fold server takes a sequence, either DNA or RNA, and predicts the lowest free energy secondary structure and a set of alternative low free energy structures called suboptimal structures. A wide variety of constraints can be applied, including, but not limited to, pairing restraints, modifications, and addition of SHAPE data.

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If you need specific help using the Fold server, please click here.

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RNAstructure tools have been updated to version which includes several improvements.
Please contact us with any questions or issues regarding this update.

Select Sequence Input:

Select Sequence File:

- OR -
Enter your sequence title and content below (replaces upload if present).
Please enter nucleotides only, no headers or comments in content.
Valid nucleotides are A, C, G, T, U, and X (unknown nucleotide). Lower case nucleotides are forced single stranded in calculation.

Sequence Title: Sequence: (Click here to add an example sequence to the box.)

Select Nucleic Acid Type:

DNA:
RNA:

Select Fold Options:

Default Data If a default value is left blank, the value is treated as if it was not changed at all. Maximum % Energy Difference: Maximum Number of Structures: Window Size: Maximum Loop Size: Temperature (K):

Optional Data Select Folding Constraints File:

Note that in order to use SHAPE intercept and/or SHAPE slope, a SHAPE constraints file must be specified. If a value is given for intercept or slope without an accompanying constraints file, the intercept or slope value is not used in calculation. Select SHAPE Constraints File: SHAPE Intercept: SHAPE Slope:

Designate Address to Email Results:

Address to Email Results:

RNAstructure

Web Servers for RNA Secondary Structure Prediction

Welcome to the Fold Web Server

Select Sequence Input:

Select Nucleic Acid Type:

Select Fold Options:

Designate Address to Email Results: