NAME

hybrid-ss-min — fold an RNA or DNA sequence

SYNOPSIS

hybrid-ss-min [OPTION]... FILE.br hybrid-ss-min --quiet [OPTION]....IR SEQUENCE ....br hybrid-ss-min --stream [OPTION]...

DESCRIPTION

hybrid-ss-min computes a minimum energy folding of the sequence(s) in FILE. If the suffix option is used, the folding is computed using the energy rules with the suffix extension; otherwise, it is computed at each temperature from tMin to tMax degrees Celsius, in increments of tInc degrees. All output files are named with a prefix which consists of the file name with the extension .seq removed. The free energy at each temperature is written to prefix.dG. The minimum energy structure is written to prefix.temperature.ct. hybrid-ss-min also writes prefix.temperature.plot and prefix.temperature.ext in the manner of hybrid-ss; each probability is either 1 or 0. A summary of the options the program was invoked with is written to prefix.run.

OPTIONS

-n, --NA=RNA2|RNA3|RNA|DNA: set nucleic acid type to RNA or DNA. Default is RNA.
-t, --tmin=REAL: set minimum temperature to REAL °C. Default is 37.
-i, --tinc=REAL: set temperature increment to REAL C°. Default is 1.
-T, --tmax=REAL: set maximum temperature to REAL °C. Default is 37.
-N, --sodium=REAL: set Sodium ion concentration to REAL molar. Default is 1.
-M, --magnesium=REAL: set Magnesium ion concentration to REAL molar. Default is 0.
-p, --polymer: use salt corrections for polymers instead of oligomers (the default).
-s, --suffix=STRING: use energy rules with the suffix STRING. Overrides --tmin, --tinc, --tmax, --sodium, --magnesium and --polymer.
-o, --output=STRING: name output files with the prefix STRING.
-f, --force=i,j[,k]: force all basepairs in the helix from i,j to i+k-1,j-k+1. If j is 0, force bases i to i+k-1 to be double-stranded; if i is 0, force bases j to j-k+1 to be double-stranded. k defaults to 1 if not specified.
-r, --prohibit=i,j[,k]: prohibit all basepairs in the helix from i,j to i+k-1,j-k+1. If j is 0, prohibit bases i to i+k-1 from pairing at all; if i is 0, prohibit bases j to j-k+1 from pairing at all. k defaults to 1 if not specified.
-R, --prohibit-range=i,j,k,l: prohibit any base from i to j from pairing with any base from k to l.
-E, --energy-only: skip computation of structure and output only prefix.dG and prefix.run. This mode uses less time and memory.
-I, --noisolate: prohibit all isolated basepairs. Isolated basepairs are helices of length 1; that is, they do not stack on another basepair on either side. (See also the --prefilter option below.)
-F, --mfold[=P[,W][,MAX]]: perform multiple (suboptimal) tracebacks in the style of mfold. P indicates the percent suboptimality to consider; only structures with energies within P% of the minimum will be output. W indicates the window size; a structure must have at least W basepairs that are each a distance of at least W away from any basepair in a previous structure. MAX represents an absolute limit on the number of structures computed. When --mfold is specified, UNAFold also writes prefix.ann and prefix.plot. These files contain the p-num values and the energy dot plot, respectively. If any arguments are not specified, they default to 5,*,100; W determined by sequence length.
-m, --maxbp=NUMBER: bases farther apart than NUMBER cannot form. Default is no limit.
-q, --quiet: interpret the arguments on the command line as sequences themselves, rather than as names of files containing sequences. No files are written, and standard output consists only of the free energies.
-c, --constraints[=FILE]: read a list of constraints from FILE. Constraints must be in the form "F i j k", "P i j k" or "R i-j k-l". These are equivalent to specifying "--force=i,j,k", "--prohibit=i,j,k" or "--prohibit-range=i,j,k,l", respectively. If FILE is not specified, it defaults to prefix.aux.
-b, --basepairs=FILE: read a list of allowable helices from FILE. Each helix consists of three whitespace-delimited numbers, which specify the starting basepair and the length of the helix. When this option is used, all basepairs except those in FILE are prohibited from forming.
--circular: treat sequences as circular rather than linear.

OBSCURE OPTIONS

--allpairs: allow basepairs to form between any two nucleotides. When --allpairs is not specified, only Watson-Crick and wobble basepairs are allowed.
-d, --debug
--maxloop=NUMBER: set the maximum size of bulge/interior loops to NUMBER. Default is 30.
--maxas=NUMBER: set the maximum asymmetry of bulge/interior loops to NUMBER. Default is 30.
--nodangle: remove single-base stacking from consideration.
--simple: make the penalty for multibranch loops constant rather than affine.
--prefilter=value1[,value2]: set the prefilter to filter out all basepairs except those in groups of value2 adjacent basepairs of which value1 can form. value2 is the same as value1 if unspecified. Default is 2 of 2. (See also the --noisolate option above.)
--stream: read sequences from standard input rather than a file. Quiet mode is implied, so that free energies are written on standard output and no files are created.

ENVIRONMENT

UNAFOLDDAT: an alternate location from which to read the energy rules. The default energy rules can be overridden with files in the current directory or in the directory pointed to by UNAFOLDDAT. hybrid-ss-min looks for each file first in the current directory, then in the directory specified by UNAFOLDDAT and last in /usr/local/share/unafold (or wherever the energy rules were installed).

REFERENCES

Markham, N. R. and Zuker, M. (2008) UNAFold: software for nucleic acid folding and hybridization. In Keith, J. M., editor, Bioinformatics, Volume II. Structure, Functions and Applications, number 453 in Methods in Molecular Biology, chapter 1, pages 3-31. Humana Press, Totowa, NJ. ISBN 978-1-60327-428-9.

Other references which may be useful may be found at http://www.unafold.org/Dinamelt/dinamelt-references.php

AUTHORS

Nick Markham <markham@alum.rpi.edu> and Michael Zuker <zukerm@alum.mit.edu>

COPYRIGHT

AVAILABILITY

Both commercial and non-commercial use of UNAFold require a license from RPI; see https://ipo.rpi.edu/invention/unafold-version-40.