De novo Viral Genome Annotator
VIGA is a script written in Python 2.7 that annotates viral genomes automatically (using a de novo algorithm) and predict the function of their proteins using BLAST and HMMER. This script works in UNIX-based OS, including MacOSX.
Before using this script, the following Python modules and programs should be installed:
- LASTZ (Harris 2007): it is used to predict the circularity of the contigs. The program is publicly available at https://github.com/lastz/lastz under the MIT licence.
- INFERNAL (Nawrocki and Eddy 2013): it is used to predict ribosomal RNA in the contigs when using the RFAM database (Nawrocki et al. 2015). This program is publicly available at http://eddylab.org/infernal/ under the BSD licence and RFAM database is available at ftp://ftp.ebi.ac.uk/pub/databases/Rfam/
- ARAGORN (Laslett and Canback 2004): it is used to predict tRNA sequences in the contig. This program is publicly available at http://mbio-serv2.mbioekol.lu.se/ARAGORN/ under the GPLv2 licence.
- PILERCR (Edgar 2007): it is used to predict CRISPR repeats in your contig. This program is freely available at http://drive5.com/pilercr/ under a public licence.
- Tandem Repeats Finder (TRF; Benson 1999): it is used to predict the tandem repeats in your contig. This program is freely available at https://tandem.bu.edu/trf/trf.html under a custom licence.
- Inverted Repeats Finder (IRF; Warburton et al. 2004): it is used to predict the inverted repeats in your contig. This program is freely available at https://tandem.bu.edu/irf/irf.download.html under a custom licence.
- Prodigal (Hyatt et al. 2010): it is used to predict the ORFs. When the contig is smaller than 100,000 bp, MetaProdigal (Hyatt et al. 2012) is automatically activated instead of normal Prodigal. This program is publicly available at https://github.com/hyattpd/prodigal/releases/ under the GPLv3 licence.
- DIAMOND (Buchfink et al. 2015): it is used to predict the function of proteins according to homology. This program is publicly available at https://github.com/bbuchfink/diamond under the GPLv3 licence. Databases must be created from FASTA files according to their instructions before running.
- BLAST+ (Camacho et al. 2008): it is used to predict the function of the predicted proteins according to homology when DIAMOND is not able to retrieve any hit or such hit is a 'hypothetical protein'. This suite is publicly available at ftp://ftp.ncbi.nlm.nih.gov/blast/executables/blast+/LATEST/ under the GPLv2 licence. Databases are available at ftp://ftp.ncbi.nlm.nih.gov/blast/db/ or created using makeblastdb command.
- HMMER (Finn et al. 2011): it is used to add more information of the predicted proteins according to Hidden Markov Models. This suite is publicly available at http://hmmer.org/ under the GPLv3 licence. Databases must be in HMM format and an example of potential database is PVOGs (http://dmk-brain.ecn.uiowa.edu/VOG/downloads/All/AllvogHMMprofiles.tar.gz).
Although you can install the programs manually, we strongly recommend the use of the Docker image to create an environment for VIGA. The link to the Docker image is https://hub.docker.com/r/vimalkvn/viga/
Before running this pipeline, you must run the 'create_db.sh' bash script to install all requested databases. In this case, the databases that the program uses are RFAM (Nawrocki et al. 2015), RefSeq Viral Proteins (Brister et al. 2015) and PVOGS (Grazziotin et al. 2017), which will be formatted automatically to be used in BLAST, DIAMOND and HMMER.
When using this program, you must cite their use:
González-Tortuero E, Sutton TDS, Velayudhan V, Shkoporov AN, Draper LA, Stockdale SR, Ross RP, Hill C (2018) VIGA: a sensitive, precise and automatic de novo VIral Genome Annotator. bioRxiv 277509; doi: https://doi.org/10.1101/277509
The program has the following two types of arguments:
|--input FASTAFILE||Input file as a nucleotidic FASTA file. It can contains multiple sequences (e.g. metagenomic contigs)|
|--diamonddb DIAMONDDB||DIAMOND database that will be used for the protein function prediction. The database MUST be for amino acids. The database must be created from a amino acid FASTA file as indicated in https://github.com/bbuchfink/diamond|
|--blastdb BLASTDB||BLAST database that will be used to refine the protein function prediction in hypothetical proteins. The database must be an amino acid one, not nucleotidic.|
|--rfamdb RFAMDB||RFAM database that will be used for the ribosomal RNA prediction. RFAMDB should be in the format "/full/path/to/rfamdb/Rfam.cm" and must be compressed accordingly (see INFERNAL manual) before running the script.|
|--modifiers TEXTFILE||Input file as a plain text file with the modifiers per every FASTA header according to SeqIn (https://www.ncbi.nlm.nih.gov/Sequin/modifiers.html). All modifiers must be written in a single line and are separated by a single space character. No space should be placed besides the = sign. For example: [organism=Serratia marcescens subsp. marcescens] [sub-species=marcescens] [strain=AH0650_Sm1] [moltype=DNA] [tech=wgs] [gcode=11] [country=Australia] [isolation-source=sputum]. This line will be copied and printed along with the record name as the definition line of every contig sequence.|
Advanced general parameters:
|--out OUTPUTNAME||Name of the outputs files without extensions, as the program will add them automatically. By default, the program will use the input name as the output.|
|--locus STRING||Name of the contigs/sequences. If the input is a multiFASTA file, please put a general name as the program will add the number of the contig at the end of the name. By default, the name of the contigs will be "LOC".|
|--gff||Printing the output as a General Feature Format (GFF) version 3. It is a flat table file with contains 9 columns of data (see http://www.ensembl.org/info/website/upload/gff3.html for more information). By default, the program will not print the GFF3 file (--gff False).|
|--threads INT||Number of threads/CPUs. By default, the program will use all available CPUs.|
|--mincontigsize INT||Minimum contig length to be considered in the final files. By default, the program only consider from 200 bp.|
Advanced parameters for contig shape prediction:
|--readlength INT||Read length for the circularity prediction (default: 101 bp)|
|--windowsize INT||Window length used to determine the origin of replication in circular contigs according to the cumulative GC skew(default: 100 bp)|
|--slidingsize INT||Sliding window length used to determine the origin of replication in circular contigs according to the cumulative GC skew(default: 10 bp)|
Advanced parameters for CRISPR detection prediction:
|--minrepeat INT||Minimum repeat length for CRISPR detection (Default: 16)|
|--maxrepeat INT||Maximum repeat length for CRISPR detection (Default: 64)|
|--minspacer INT||Minimum spacer length for CRISPR detection (Default: 8)|
|--maxspacer INT||Maximum spacer length for CRISPR detection (Default: 64)|
Advanced parameters for genetic code:
|--gcode NUMBER||Number of GenBank translation table. At this moment, the available options are:
Advanced parameters for GenBank division:
|--typedata BCT|CON|VRL|PHG||GenBank Division: One of the following codes:
Advanced parameters for protein function prediction based on homology using DIAMOND:
|--diamondevalue FLOAT||DIAMOND e-value threshold. By default, the threshold will be 1e-05.|
|--diamondidthr FLOAT||DIAMOND identity threshold to consider that a protein belong to a specific hit. By default, the threshold is 50.0 %|
|--diamondcoverthr FLOAT||DIAMOND coverage threshold to consider that a protein belong to a specific hit. By default, the threshold is 50.0 %|
Advanced parameters for protein function prediction based on homology using BLAST:
|--blastexh||Use of exhaustive BLAST to predict the proteins by homology according to Fozo et al. (2010). In this case, the search will be done using a word size of 2, a gap open penalty of 8, a gap extension penalty of 2, the PAM70 matrix instead of the BLOSUM62 and no compositional based statistics. This method is more accurate to predict the functions of the proteins but it is slower than BLAST default parameters. By default, exhaustive BLAST is disabled.|
|--blastevalue FLOAT||BLAST e-value threshold. By default, the threshold will be 1e-05.|
|--blastidthr FLOAT||BLAST identity threshold to consider that a protein belong to a specific hit. By default, the threshold is 50.0 %|
|--blastcoverthr FLOAT||BLAST coverage threshold to consider that a protein belong to a specific hit. By default, the threshold is 50.0 %|
Advanced parameters for protein function annotation based on Hidden Markov Models using HMMer:
|--nohmmer||Running the program without using HMMer to predict protein function. In this case, the program will run fast. By default, this option is DISABLED.|
|--hmmerdb HMMDB||HMMer Database that will be used to add additional information for all proteins according to Hidden Markov Models. This database must be in HMM format and it is mandatory if --nohmmer is disabled."|
|--hmmerevalue FLOAT||HMMer e-value threshold. By default, the threshold is 1e-03.|
|--hmmeridthr FLOAT||HMMer identity threshold. By default, the threshold is 50.0 %|
|--hmmercoverthr FLOAT||HMMer coverage threshold. By default, the threshold is 50.0 %|
An example of execution (using only basic parameters) is:
python VIGA.py --input contigs.fasta --diamonddb databases/refseq_viral_proteins --blastdb databases/refseq_viral_proteins --hmmerdb databases/PVOGS.hmm --rfamdb databases/Rfam.cm --modifiers modifiers.txt
Another example (this time disabling the use of HMMer, which allows a fast execution of the pipeline) is:
python VIGA.py --input contigs.fasta --diamonddb databases/refseq_viral_proteins --blastdb databases/refseq_viral_proteins --nohmmer --rfamdb databases/rfam/Rfam.cm --modifiers ../modifiers.txt
Finally, in case that you need to run the pipeline in a server, computer cluster or supercomputer, using the --threads parameter is highly recommended:
python VIGA.py --input contigs.fasta --diamonddb databases/refseq_viral_proteins --blastdb databases/refseq_viral_proteins --nohmmer --rfamdb databases/rfam/Rfam.cm --modifiers ../modifiers.txt --threads 10
VIGA can be integrated into Galaxy using the wrapper included in this repository.
Docker should first be installed and working on the server where this Galaxy instance is setup. The user running Galaxy should be part of the docker user group.
Download or clone this repository (as a submodule) in the tools directory of the Galaxy installation.
Update config/tool_conf.xml to add the VIGA wrapper in a relevant section of the tool panel. For example, "Annotation".
<section id="annotation" name="Annotation"> <tool file="viga/wrapper.xml" /> </section>
Copy (or update the file if it is already present) the included tool_data_table_conf.xml.sample file to config/tool_data_table_conf.xml.
<!-- VIGA databases --> <tables> <table name="viga_blastdb" comment_char="#"> <columns>value, dbkey, name, path</columns> <file path="tool-data/viga_blastdb.loc" /> </table> <table name="viga_diamonddb" comment_char="#"> <columns>value, dbkey, name, path</columns> <file path="tool-data/viga_diamonddb.loc" /> </table> <table name="viga_rfamdb" comment_char="#"> <columns>value, dbkey, name, path</columns> <file path="tool-data/viga_rfamdb.loc" /> </table> <table name="viga_hmmdb" comment_char="#"> <columns>value, dbkey, name, path</columns> <file path="tool-data/viga_hmmdb.loc" /> </table> </tables>
Copy the .loc.sample files from viga/tool-data to galaxy/tool-data and rename them as .loc. For example:
viga_blastdb.loc.sample -> viga_blastdb.loc
Update database paths in .loc files Edit the following files in the tool-data directory and add paths to corresponding databases
Create or update the Galaxy job configuration file
If the file config/job_conf.xml does not exist, create it by copying the template config/job_conf.xml.sample_basic in the Galaxy directory. Then add a Docker destination for viga. Change
docker_volumesto the location where your databases are stored. Here is an example:
<?xml version="1.0"?> <!-- A sample job config that explicitly configures job running the way it is configured by default (if there is no explicit config). --> <job_conf> <plugins> <plugin id="local" type="runner" load="galaxy.jobs.runners.local:LocalJobRunner" workers="4"/> </plugins> <handlers> <handler id="main"/> </handlers> <destinations default="local"> <destination id="local" runner="local"/> <destination id="docker" runner="local"> <param id="docker_enabled">true</param> <param id="docker_sudo">false</param> <param id="docker_auto_rm">true</param> <param id="docker_volumes">$defaults,/data/databases:ro</param> </destination> </destinations> <tools> <tool id="viga" destination="docker"/> </tools> </job_conf>
Restart Galaxy. The tool will now be ready to use.
HISTORY OF THE SOURCE CODE:
- v.0.11.0 - Improved the speed of the code. Now the pipeline have a different strategy: instead of running all analyses per individual contigs, these are applied altogether. Moreover, the pipeline first runs DIAMOND to annotate all proteins according to homology and, later, BLAST is executed to try to improve the annotation of these hypothetical proteins (including those who have no match). Optionally, HMMer could be executed to add more additional information about the proteins based on HMM databases such as PVOGs (Grazziotin et al. 2017). Recently, the use of '-max_target_seqs' in BLAST was shown to generate non-reproducible data, and now it is not recommended to use it (Shah et al. in press). We fixed this issue in this pipeline removing such parameter for all homology-based searches.As a consequence of all, the source code was rewritten entirely, as well as there are several changes in the parameters. Moreover, added a new script to download and create the required databases in a quick a single step.
- v 0.10.4 - Fixed error when the module BCBio is invoked. Now it is required the module BCBio.GFF instead of the BCBio one.
- v 0.10.3 - New output: all protein sequences per contig.
- v 0.10.1 - Fixed error when the start coordinate of a gene is equal to one. In these cases, genes were annotated as if they started in the position zero (which it has no biological logic). Now, the program should be able to deal with these genes, annotate them from the position 1. Moreover, added new terms to reduce all non-informative protein descriptions before running the decision tree.
- v 0.10.0 - Added the prediction of the origin and terminus of replication for circular contigs based on the cumulative GC skew (based on the iRep software - Brown et al (2016)). After detecting the origin coordinate, the chromosome is realigned from the origin. As a consequence of that, two new parameters ("--windowsize" and "--slidingsize") were added to determine the window size and the sliding window size respectively. Moreover, fixed error with the start position of the genes in the GenBank files, which were not related to the amino acid sequences and made that the sequence length was not multiple of three. Finally, added "/locus_tag" in the putative genes in the GenBank files
- v 0.9.1 - Fixed a bug in creation of logfile
- v 0.9.0 - Improved the BLAST/DIAMOND and HMMER parsers to reduce all non-informative protein descriptions (e.g. "hypothetical protein", "ORF") before running the decision tree algorithm. Additionally, a new output file (logfile.txt) is generated to harbour the information about the old contig names and the new ones (generated by the program).
- v 0.8.2 - Fixed issue with DIAMOND when there is no protein sequence as input.
- v 0.8.1 - The program is able to deal with tmRNA sequences in a proper way. There were an error due to the "(Permuted)" flag in ARAGORN files in some cases. Additionally, the name of the "--fast" and "--ultrafast" parameters were changed to "--nohmmer" and "--noblast" as their descriptions are more accurate.
- v 0.8.0 - Added the "--ultrafast" parameter. In this case, DIAMOND (Buchfink et al. 2015) will be launch to predict protein function according to homology instead of BLAST. It is faster than the "fast" mode but the sensitivity of the annotations will not be the highest.
- v 0.7.1 - Fixed error on the "--fast" parameter. All proteins that had no hits in BLAST analyses were not parsed properly. By now, these are identified as "Hypothetical proteins" in all files.
- v 0.7.0 - Added the "--fast" parameter. In this case, the program will launch BLAST (but not PHMMER) to annotate protein function. In this case, the program will be as fast as Prokka (Seemann 2014) but the annotations will not be accurate. As a consequence of this new parameter, the "--hmmdb" parameter is only mandatory when this flag is NOT used (as by default).
- v 0.6.2 - Removed the "--noparallel" parameter. After doing time benchmarks to test the speed of BLAST and HMMER when they are run using the multithreading option and as a parallel program, we found that BLAST tends to be faster using multithreading option while HMMER had the opposite behavior. For that, we decided to consider only the parallelization of HMMER and to run BLAST using multiple threads.
- v 0.6.1 - Fixed issue with parallel HMMER (the program tend to take all available CPUs independently of the parsed arguments) and with the BLAST/HMMER decision trees (typos).
- v 0.6.0 - Replaced HHSUITE by HMMER 3.1 to predict protein function according to Hidden Markov Models. In a recent benchmark (as well as internal ones), we found that HHPred tends to be the slowest program to predict protein function (compared with PHMMER and BLASTP). Additionally, HMMER had a high accuracy when proteins are annotated (Saripella et al. 2016). Moreover, it has the advantage that the databases must be in FASTA format (such UniProt and, even, PFAM), which it is a standard format. For all these reasons, we replaced HHSUITE by HMMER 3.1. Additionally, fixed small issues related to the GenBank file (omission of the contig topology as well as the name of the locus).
- v 0.5.0 - Implemented PILER-CR to predict CRISPR repeats regions. Additionally, fixed errors in the rRNA prediction and inverted and tandem repeats.
- v 0.4.0 - Replaced RNAmmer v 1.2. by INFERNAL 1.1 + RFAM to predict rRNA in the contigs. In this case, you must specify where you have downloaded the RFAM database using the "--rfamdb" option.
- v 0.3.0 - Implemented RNAmmer v 1.2 to predict rRNA in the contigs. If such program is able to predict ribosomal genes, a warning is printed (as viral sequences do not have ribosomal genes).
- v 0.2.0 - Added parallelization of BLAST and HHSUITE. To do that, GNU Parallel (Tange 2011) is required. To disable this option, run the program with the "--noparallel" option.
- v 0.1.0 - Original version of the program.
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