RNAPKplex — ViennaRNA Package

# RNAPKplex

RNAPKplex - manual page for RNAPKplex 2.7.2

## Synopsis

    RNAPKplex [OPTION]...

## DESCRIPTION

RNAPKplex 2.7.2

predicts RNA secondary structures including pseudoknots

Computes RNA secondary structures by first making two sequence intervals accessible and unpaired using the algorithm of RNAplfold and then calculating the energy of the interaction of those two intervals. The algorithm uses O(n^2*w^4) CPU time and O(n*w^2) memory space. The algorithm furthermore always considers dangle=2 model.

It also produces a PostScript file with a plot of the pseudoknot-free secondary structure graph, in which the bases forming the pseuodknot are marked red.

Sequences are read in a simple text format where each sequence occupies a single line. Each sequence may be preceded by a line of the form .. code:

    > name

to assign a name to the sequence. If a name is given in the input, the PostScript file “name.ps” is produced for the structure graph. Other- wise the file name defaults to PKplex.ps. Existing files of the same name will be overwritten. The input format is similar to fasta except that even long sequences may not be interrupted by line breaks, and the header lines are optional. The program will continue to read new sequences until a line consisting of the single character @ or an end of file condition is encountered.

-h, --help

  Print help and exit

--detailed-help

  Print help, including all details and hidden options, and exit

--full-help

  Print help, including hidden options, and exit

-V, --version

  Print version and exit

-v, --verbose

  Be verbose. (default=off)

  Lower the log level setting such that even INFO messages are passed through.

### I/O Options:

> Command line options for input and output (pre-)processing

--noconv

  Do not automatically substitute nucleotide “T” with “U”.

  (default=off)

--log-level=level

  Set log level threshold. (default=”2”)

  By default, any log messages are filtered such that only warnings (level 2) or errors (level 3) are printed. This setting allows for specifying the log level threshold, where higher values result in fewer information. Log-level 5 turns off all messages, even errors and other critical information.

--log-file[=filename]

  Print log messages to a file instead of stderr. (default=”RNAPKplex.log”)

--log-time

  Include time stamp in log messages.

  (default=off)

--log-call

  Include file and line of log calling function.

  (default=off)

### Algorithms:

> Select additional algorithms which should be included in the calculations.

-c, --cutoff=FLOAT

  Only consider unpaired probabities > cutoff for putative PK sites.

  (default=”1e-6”)

-e, --energyCutoff=DOUBLE

  Energy cutoff or pseudoknot initiation cost. Minimum energy gain of a pseudoknot interaction for it to be returned. Pseudoknots with smaller energy gains are rejected.

  (default=”-8.10”)

-s, --subopts=DOUBLE

  print suboptimal structures whose energy difference of the pseudoknot to the optimum pseudoknot is smaller than the given value.

  (default=”0.0”)

  NOTE: The final energy of a structure is calculated as the sum of the pseudoknot interaction energy, the penalty for initiating a pseudoknot and the energy of the pseudoknot-free part of the structure. The `-s` option only takes the pseudoknot interaction energy into account, so the final energy differences may be bigger than the specified value (default=0.).

--betaScale=DOUBLE

  Set the scaling of the Boltzmann factors. (default=”1.”)

  The argument provided with this option is used to scale the thermodynamic temperature in the Boltzmann factors independently from the temperature of the individual loop energy contributions. The Boltzmann factors then become `exp(- dG/(kT*betaScale))` where `k` is the Boltzmann constant, `dG` the free energy contribution of the state and `T` the absolute temperature.

-S, --pfScale=DOUBLE

  In the calculation of the pf use scale*mfe as an estimate for the ensemble free energy (used to avoid overflows).

  (default=”1.07”)

  The default is 1.07, useful values are 1.0 to 1.2. Occasionally needed for long sequences.

### Energy Parameters:

> Energy parameter sets can be adapted or loaded from user-provided input files

-T, --temp=DOUBLE

  Rescale energy parameters to a temperature of temp C. Default is 37C.

  (default=”37.0”)

-P, --paramFile=paramfile

  Read energy parameters from paramfile, instead of using the default parameter set.

  Different sets of energy parameters for RNA and DNA should accompany your distribution. See the RNAlib documentation for details on the file format. The placeholder file name `DNA` can be used to load DNA parameters without the need to actually specify any input file.

-4, --noTetra

  Do not include special tabulated stabilizing energies for tri-, tetra- and hexaloop hairpins.

  (default=off)

  Mostly for testing.

--salt=DOUBLE

  Set salt concentration in molar (M). Default is 1.021M.

### Model Details:

> Tweak the energy model and pairing rules additionally using the following parameters

--noLP

  Produce structures without lonely pairs (helices of length 1).

  (default=off)

  For partition function folding this only disallows pairs that can only occur isolated. Other pairs may still occasionally occur as helices of length 1.

--noGU

  Do not allow GU pairs.

  (default=off)

--noClosingGU

  Do not allow GU pairs at the end of helices.

  (default=off)

--nsp=STRING

  Allow other pairs in addition to the usual AU,GC,and GU pairs.

  Its argument is a comma separated list of additionally allowed pairs. If the first character is a “-” then AB will imply that AB and BA are allowed pairs, e.g. `--nsp=`”-GA” will allow GA and AG pairs. Nonstandard pairs are given 0 stacking energy.

--helical-rise=FLOAT

  Set the helical rise of the helix in units of Angstrom.

  (default=”2.8”)

  Use with caution! This value will be re-set automatically to 3.4 in case DNA parameters are loaded via `-P` DNA and no further value is provided.

--backbone-length=FLOAT

  Set the average backbone length for looped regions in units of Angstrom.

  (default=”6.0”)

  Use with caution! This value will be re-set automatically to 6.76 in case DNA parameters are loaded via `-P` DNA and no further value is provided.

## REFERENCES

If you use this program in your work you might want to cite:

R. Lorenz, S.H. Bernhart, C. Hoener zu Siederdissen, H. Tafer, C. Flamm, P.F. Stadler and I.L. Hofacker (2011), “ViennaRNA Package 2.0”, Algorithms for Molecular Biology: 6:26

I.L. Hofacker, W. Fontana, P.F. Stadler, S. Bonhoeffer, M. Tacker, P. Schuster (1994), “Fast Folding and Comparison of RNA Secondary Structures”, Monatshefte f. Chemie: 125, pp 167-188

R. Lorenz, I.L. Hofacker, P.F. Stadler (2016), “RNA folding with hard and soft constraints”, Algorithms for Molecular Biology 11:1 pp 1-13

The energy parameters are taken from:

D.H. Mathews, M.D. Disney, D. Matthew, J.L. Childs, S.J. Schroeder, J. Susan, M. Zuker, D.H. Turner (2004), “Incorporating chemical modification constraints into a dynamic programming algorithm for prediction of RNA secondary structure”, Proc. Natl. Acad. Sci. USA: 101, pp 7287-7292

D.H Turner, D.H. Mathews (2009), “NNDB: The nearest neighbor parameter database for predicting stability of nucleic acid secondary structure”, Nucleic Acids Research: 38, pp 280-282

## AUTHOR

Wolfgang Beyer

## REPORTING BUGS

If in doubt our program is right, nature is at fault. Comments should be sent to rna@tbi.univie.ac.at.