Questions tagged [alignment]

These questions are about sequence alignment.

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3answers
61 views

Calculate genome coverage and depth from alignment

I have a .bam alignment file and a genome reference .fasta file. I am looking for a easy to use tool (that I can reference in a publication) to calculate the percentage coverage of the reference by ...
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0answers
34 views

Given a multiple sequence alignment, how do I output all of the non-consensus characters by location?

I have an MSA from MAFFT (as a FASTA file; there are several sequences in the MSA), and I would like to quantify the "variants" between these sequences. What is the standard tool to do ...
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0answers
122 views

How to assign the best gap penalty and gap extension penalty using BLOSUM65 [closed]

For an assignment I must do a pairwise optimal local alignment using BLOSUM65 and five protein sequences. The algorithm I want to use is the Smith-Waterman. Context protein sequencing using Blastp: ...
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1answer
104 views

How should I deal with segmental duplications when aligning NGS reads to a reference genome?

This is a follow-up of my other question. I have been having trouble calling variants in the human SMN1 and SMN2 genes, because the human genome has a large segmental duplication there and these two ...
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1answer
162 views

Read alignment using Bowtie2

So this is related to CRISPR-CAS9. I am working with off-target predictions for my thesis and was looking at all scientific papers related to CRISPR. I found one and decided to use their datasets. The ...
4
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0answers
158 views

R Biostrings pairwiseAlignment to BAM

The R package Biostrings has a function to create a pairwiseAlignment from pattern and subject sequences. So far I can save the result into a text file using writePairwiseAlignments. I would like to ...
3
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0answers
58 views

Trying to show the gaps of each seq on bio::Graphics after converting clustalw

I want a box representing each sequence, positioned as they are in the alignment and with gaps shown as breaks in the each box. I've been having trouble for a while with this and have been trying to ...
3
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1answer
50 views

RNASeq read coverage in protein space?

I used samtools depth to find the per base-pair read coverage over a number of isoform contigs from my Trinity assembly. I have also conducted a multiple sequence ...
2
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0answers
20 views

use Kallisto in galaxy

I want to use kalisto for sequence alignment in Galaxy. i found this field empty: there is no option available for the reference transcriptome. how I can get one? Can I let the other configuration by ...
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1answer
65 views

How to change sequence format in my alignment file?

I have fasta file with alingned several sequences (from MUSCLE), when I open it (e.g. notepad++) they look like: And I want dot format of identities like and then save it in txt file. I failed ...
2
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1answer
49 views

Global alignment between two sequence X and Y with maximum number of identical matches

If 2 protein sequence X of length m and Y of length n and if there are several highest scoring global alignments, then I want to get one alignment that has largest number of columns in which a letter ...
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1answer
17 views

Total pairs of amino acid substitution

I am reading a blog and it says: The numbers for identities and replacements used for calculating the overall alignment score in the expression above are usually presented in the form of a 20 x 20 ...
4
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1answer
62 views

Is there a modern alignment tool tailored for transmembrane regions?

I am looking for a project or tool that allows programmatic pairwise alignments of proteins but that takes care with transmembrane regions of proteins. TM regions are traditionally too information ...
9
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1answer
165 views

Chimera Alignments

I have a structure with two subunits. I am trying to show movement of the C-terminal subunit upon ligand binding by superposition with another structure from the same strain in the apo form. I want ...
1
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1answer
31 views

where to find sample contig data

Where or How can I find contigs? I am trying to learn Bioinformatics and I want to make a reference-based gene search. I also want to align contigs with a given reference sequence. From NCBI other ...
3
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1answer
133 views

Glocal\semi-local\Hybride Globale-Local alignment with Python

I was looking for a simple way to do a glocal alignment. The case I have is I have a small sequence which should be find in a bigger one, thus typically a glocal alignment. Also I can not Install ...
4
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0answers
127 views

convert supplementary reads to primary in sam or bam

I have a problem with a tool, that possibly ignores supplementary reads. I want to find out a bit how this tool works by converting all supplementary reads to primary reads, and then change the names ...
0
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1answer
64 views

Supplementary aligments in VAF

This question has also been asked on Biostars I have a doubt, are supplementary alignment usually considered when the variant allele frequency is calculated? Thanks a lot. In my case I have some ...
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1answer
17 views

Understanding ViennaRNA RNAdistance scoring table

I'm trying to compare the output of 2 different algorithms of RNA structure prediction (my implementation of Nussinov vs RNA-mfold algorithm) using the RNAdistance algorithm that is part of ViennaRNA ...
1
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1answer
42 views

Median string problem & multiple sequence alignment

I read about the median string problem as an introduction to the multiple sequence alignment, however none of the MSA algorithms used seems to be using the idea of finding the median string. To my ...
0
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1answer
97 views

TopHat2 versus HISAT2 inner workings

In my intro to bioinformatics course, we mentioned that TopHat2 and HISAT2 will both try to align as many reads as possible to the reference genome (TopHat2 has been superseded by HISAT2). For the ...
2
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1answer
63 views

Translating a genome sequence into possible frames

I have a sequence below from MYC gene about which I need to translate the sequence in all possible frames AND identify (for each frame) which codons are actually used in MYC ...
3
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2answers
2k views

Error while calling bcftools mpileup - Failed to open -: unknown file type

I have sequenced a bacterial genome with a GridIon from ONT. Basically what I want to check is whether or not trimming 50 bps at the beginning of the reads will improve alignment against the reference ...
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1answer
39 views

File format of substitution matrix in clustalw

I need to set the substitution matrix used by command line CLUSTALW when comparing DNA sequences to: 0 -1 -1 -1 -1 0 -1 -1 -1 -1 0 -1 -1 -1 -1 0 from my ...
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0answers
83 views

STAR aligner multiple fastq files

I’m using STAR to align fastq files from SMART-seq2. I have raw data folder containing sub-folders with samples names the sub-folders each contain fastq file. How can I make a bash command in order ...
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1answer
62 views

merge the matrix from computematrix of deeptools

I have several matrix from computematrix of deeptools. I need to merge two of them using "computeMatrixOperations cbind -m input1.mat.gz input2.mat.gz -o output.mat.gz" but I am running to error "/...
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1answer
112 views

How to calculate mutation rate and mutation sites in a genome using FASTA file?

I have 6 viral genome sequences of the same virus and 1 reference sequence in FASTA format. How I can identify mutations and mutation sites in those genomes using FASTA sequences but how I can do ...
3
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2answers
246 views

Frequency of specific viral sequence in .BAM or .fastq

I was wondering if anyone had any experience 'counting' the frequency of a particular viral sequence in an individual's fastq sequence. So basically, counting the number of occurrences of a particular ...
1
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1answer
61 views

Assessing PyMol sequence alignment object

I use cealign in PyMol for structure alignment. Instead of visualization, I want to return the alignment object to my python script for further analysis. Is there a function to return the object ...
1
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1answer
27 views

Measure the purifying selection for certain taxa along a phylogeny

I am posting this message because I need clarity about the analysis I want to perform. In my analysis, I have a homologous gene in 13 species, and I would like to evaluate the selection pressure of ...
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0answers
6 views

Mutated residue number shown wrong in foldX yasara

I am trying to mutate phenylalanine 274 position in Uracil DNA glycosylase with alanine. The pDB file has the protein starting from 82nd residue. After the repair the console shows FA161A. The residue ...
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2answers
45 views

What programs account for structural alignment of different parts of distant homologs which have significant structural differences?

If there is a need to perform structural alignment of different parts of distant homologs, which program one should use? Since distant homologs often have significant structural changes, meaning the ...
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0answers
28 views

Why do I get cytosine to guanine/adenine transitions in bisulphite treated sequences?

I got my sequencing results (bisulphite treated and non treated sequences of same species Allium cepa) and now I have to do analysis in Cymate online tool. I prepared all sequences as it is written in ...
11
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1answer
4k views

Better aligner than bowtie2?

Bowtie2 is probably the most widely used aligner because of it's speed. Burrow-wheeler (BW) algorithms (including bwa) tend to ...
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0answers
31 views

BAM file filteing to remain best isoform

I ran HiSat2, MarkDuplicate, removed reads with the lower quality score than 40 and finally only kept properly paired reads. After the BAM filtering steps, I used the Scallop results with TransDecoder....
0
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1answer
34 views

Display a score or graph to visualize the degree of conservation of each residue from alignment data

I would like to display a score or graph to visualize the degree of conservation of each residue from the amino acid alignment data. If possible, I'd like to extract the parts of the game that scored ...
0
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1answer
22 views

Installation of PRANK MSA in WLS Ubuntu 20.04 LTS

I want to install PRANK on the Windows 10 Linux subsystem (Ubuntu 20.04 LTS), I have followed the installation instructions to no avail. ...
1
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1answer
108 views

why in RNA seq don't we only use reference transcriptome?

I would like to ask why in RNA seq analysis (alignment step) we use sometimes reference genome instead of reference transcriptome? thank you!
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0answers
24 views

What are the symbols of $*$ and '$\_$' in an unknown alignment format for HLA data from the IMGT dataset?

Has anyone worked with the IMGT HLA database/dataset before? IMGT-HLA git repo they have some convenient text files (eg. link to gene A .txt file) with the genomic data for the different alleles of ...
3
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1answer
216 views

Difference between genome assembly and genome sequence alignment to a reference to find structural variants

I'm trying to determine what the difference and benefits of genome assembly and genome sequence alignments are when trying to identify structural variants or transposons in populations. I've been ...
4
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1answer
412 views

How to map short sequences to long reads, recovering all multiply-mapped high-quality matches

The dilemma: I have around one million short sequences (21 bp to several 100s of basepairs) for which I need to identify all occurrences of in 20-30x coverage noisy long reads (both pacbio and ONT). ...
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0answers
188 views

bedtools coverage - Report the depth at each position in each A feature

I am using bedtools coverage to compute the sequencing depth at every positions of a chromosome but it didn't work as I expected. Instead it reported 0 coverage at every positions. This is how I did ...
2
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0answers
31 views

Alignment using secondary and tertiary features of DNA

I m trying to align different sequences of length not greater than 50 bp. Could I incorporate additional information such as stacking energy, entropy, bonds etc as additional criteria in the alignment?...
2
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1answer
24 views

which is the right prosite pattern?

I would like to ask if the right Prosite pattern for this multiple alignment: Is it this: A-T-[AT]-G-x-C-[AGC]-C-x(1,4)-A or this: ...
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0answers
81 views

How can I interpret multiple alignment results?

I would like to ask how I can interpret objectively multiple alignment results. I have used JALVIEW and TCOFFEE. I would like to ask if consistency score plays any role in the interpretation? I ...
2
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1answer
227 views

How to extract unmatched reads using bwa and samtools?

I have a single read (NOT paired) that I need to pass through the workflow described in Beauclair et al. paper (free version here https://rnajournal.cshlp.org/content/24/10/1285.long) for identifying ...
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1answer
202 views
3
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1answer
2k views

How do I find split reads?

How can I detect a split read in a BAM file? Is there any sign in the CIGAR string that describes split read?
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1answer
77 views

Why use Needleman-Wunsch if there is no way to evaluate the statistical significance

I thought that Needleman-Wunsch is the best approach to align sequences. However, I read that it is impossible to evaluate the statistical significance of the alignment if you do global alignment. So ...
4
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1answer
161 views

Test to determine if two genes/exons share the same evolutionary histories?

In classic phylogenetic inference one is usually given various orthologue sequences of a given gene across various species. Those sequences are then multiple aligned and used to construct a ...