Bioinformatics connects life sciences and quantitative sciences, typically involving the application of software and algorithms to solve computationally intensive questions, such as those in genomics, sequence analysis, and systems biology. Questions tagged Bioinformatics should have a direct ...

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How do I use BEAST for divergence time estimation in this case?

I am interested in using BEAST to find the divergence time estimates of species separations within a genus of frogs. The genus separated from a outgroup taxon I have chosen around 80 million years ...
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1answer
63 views

What are pseudoknots?

I'm trying to get my head around what a pseudoknot is and how I can identify them given some RNA string. For example, suppose I have a string s = CGUUGUGUACACGAUAGUACAU. Suppose the two longest ...
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1answer
287 views

What is the difference between gene and CDS annotations?

I have a bunch of sequence files fetched from the EBI ENA and I'm trying to find the end of the 5' UTR for specific genes. The UTR itself doesn't seem to be annotated in most sequence files I have. ...
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2answers
247 views

Relative microRNA comparison from from TCGA data?

I have a conceptual question that I was hoping someone could answer. Can I say that microRNA A is expressed x-fold greater than microRNA B directly from the TCGA miRseq data? Can I do this after ...
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1answer
195 views

How to select genes before log2 ratio on a RNASeq gene expression matrix, based on signal median

I want to transform a TCGA mRNA expression matrix (in linear data format) to log2-ratios and then run a feature (gene) selection, selecting the 1000 most variant genes (genes with higher standard ...
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28 views

EMBOSS matcher and supermatcher - incongruent results?

I am trying to align a sequence to the mouse genome. I know a priori that part of my sequence should align to chromosome 9, but not all of it. I gathered that EMBOSS' ...
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52 views

how to extract promoter regions given a TF binding site

I have constructed a PWM and want to test its accuracy. Scanning an entire chromosome (chr3, hg18) yields very high false positives (magnitudes higher than the true positives). Scanning the entire ...
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25 views

How can I classify Breast Cancer if I have incomplete receptor information?

I have a clinical data table for a cohort of Breast Cancer patients and I want to classify them as being either triple negative or triple positive. You can find the file here. For some of the ...
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2answers
95 views

Protein Structure Parameters

I'm wondering about the minimal set of parameters necessary to define a protein's structure. My understanding is that the backbone geometry is defined by the phi and psi angles (torsion angles), and ...
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2answers
111 views

Do variant callers miss rare variants in reference?

Generally variant calling programs (such as GATK-UnifiedGenotyper) look for differences between reference genome and submitted sequence. However, we all know that reference genome consist rare ...
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2answers
152 views

Where can I find mutation datasets for cancer?

My lab has been using TCGA data (somatic mutations and clinical data) to develop panels of genes and of mutations we expect to see in certain cancer populations. We'd like to validate our panels by ...
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1answer
104 views

Visualising a subset of the tree of life

I understand that many curated trees of life already exist (eg http://tolweb.org/tree/) but is there any website that allows one to input a list of organisms, and then produce the current best guess ...
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1answer
103 views

Stockholm format to dot-brackets format?

I need to convert all my sequences in a Stockholm format into this: ...
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67 views

How to characterise a protein family in a putative genome island?

We have sequenced the genome of 200 bacterial strains belonging to the same species, a swine bacterial pathogen. In a previous work, it was observed that a protein family of adhesins is present in ...
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2answers
390 views

What is the meaning of dots and dashes in clustalw?

I am converting outputs in stockholm format to clustalw using ...
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1answer
101 views

Is using Hidden Markov Models to find homologues sensible in abstract, short sequences?

HMM alignment tools like hhpred excel at finding subtle homologues of folded proteins that simpler scoring techniques (such those used in BLAST algorithms) would miss. I am only looking at a small ...
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2answers
63 views

All UniprotIDs of a cancer pathway

I need to download all uniprotIDs of a cancer pathway, say the AKT Signaling. It may be super easy, but I don't know which resource to look at since it is a new field. How/where do I find these?
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1answer
166 views

What do “e” “-” “C” and “E” mean in this output?

I have given an input of this protein sequence: MEPVDPRLEPWKHPGSQPKTACTTCYCKKCCFHCQVCFTTKALGISYGRKKRRQRRRPPQGSQTHQVSLSKQPTSQPRGDPTGPKE from this website along ...
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1answer
770 views

How are we able to find the specific sites at which DNA binding proteins bind?

We know that some DNA binding proteins are site specific, that is they recognise and bind to a specific nucleotide sequence. My question is how can we precisely tell at which sites they bind? Is it ...
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1answer
54 views

What is a positive epitope fragment

What is a positive epitope fragment? I found one paper on the subject: COBEpro: a novel system for predicting continuous B-cell epitopes by Michael J. Sweredoski and Pierre Baldi
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2answers
139 views

How to retrieve full gene names list and Entrez gene IDs and other annotation information from HUGO gene name list (in R or any)?

How to retrieve full gene names and Entrez gene IDs and other annotation information from HUGO gene name list (in R or any other software or language)? Is it possible vice versa: having full gene ...
2
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1answer
180 views

How do you convert mtDNA sequences in FASTA to FSTAT format?

I've got control region sequence data from a population of shark and I'm looking to convert this from FASTA to FSTAT in order to calculated the effective population size of females. The software I ...
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2answers
294 views

How to do whole genome sequence alignment in R or Ruby/C++, any good language? [closed]

I need to perform tuberculosis mutation analysis. First step I need to do is to align sequences in fasta format against one reference file. i tried CLC genomics workstation --- it hangs on 60 000 ...
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1answer
181 views

What to do if microarray t-test, ANOVA, SAM and LImma show various selected significant genes?

Need advice: how to approach discrepancy in differential microarray gene expression test results: what to do if ANOVA, ttest, SAM and Limma procedures show different results and especially more ...
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1answer
95 views

How to do a whole genome analysis of Multidrug-resistant Mycobacterium tuberculosis

I'm looking for tutorials and software that can help me study whole genome sequence data is and genome wide associations. I have Matlab and Bioconductor R so anything involving those packages would be ...
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1answer
103 views

Whole genome sequence analysis software

Please help to choose Bioconductor R packages and other software for the whole genome sequence data analysis and, in particlular, the goals of false discovery mutation rate, mutations exclusion, ...
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2answers
88 views

Aligning multiple sequences in heterogeneous group

I have a list of ~200 DNA sequences, representing probably 50 different genomic regions but they're all mixed up. For example, if I have seq1, seq2.... seq10, ...
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1answer
58 views

Supercomputer and undergraduates [closed]

Is it common for an undergraduate to run their thesis (evolutionary genomics) in a supercomputer? In my country, few supercomputers exist, but I'm not sure how it is for bachelors in the US or Europe. ...
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1answer
55 views

how to reconcile PDB structures' sequences via Uniprot references?

I’m trying to reconcile structures in PDB entries with their sequences as reported in their chemList.polymer.dbref entries. E.g.: considering structures for HIV ...
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0answers
38 views

What genetic distance model should be used when calculating genetic differences in Arelquin?

I'm using Arelquin to look at the genetic structure between a number of different populations. I want to compare the populations by producing pairwise FST values, however I don't know what model for ...
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0answers
34 views

Download FunCat Database for Programmatic Access

I am enriching RNA-seq data for the fungus Neurospora crassa and would like to be able to search the genome by functional category, determine similarity of genes by category membership, and any other ...
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2answers
103 views

Downloading specific yeast genes in an automated manner?

I have 6 genes of Candida albicans yeast namely orf19.723, orf19.5908, orf19.610, ...
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0answers
99 views

How do I import FASTA files into Haploview?

I'm trying to produce a haplotype network and so have decided to use the software haploview. However I'm having some problems importing my sequences into the software. I Have my sequences in a FASTA ...
9
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1answer
474 views

Mass spectrometry versus western blotting for validation

I have mass spectrometry data (LC-MS/MS) from rat cortices under either drug or control treatments. The results were performed in triplicate (three pairs of rats, drug or control per pair). In ...
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1answer
137 views

Is it possible to dock multiple ligands with the target?

Is it possible to dock multiple ligands with a target? If so, what is the suitable software used for? -- Is it possible to fix specific docking region for the target (or) automatic?
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1answer
52 views

STRING ID - allelic differences and splice variants

STRING has protein (amino acid sequences) mapped to a single gene ID. I have these doubts with respect to STRING ID. I find that 1.All alleles of a single gene share the same STRING ID and ...
8
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1answer
117 views

How to validate the regulatory interactions inferred from gene expression data?

My algorithm learns regulatory interaction between genes using Bayesian Network approach from gene expression data. After the algorithm has converged to a network of interacting genes, how to validate ...
2
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3answers
189 views

fastq-dump using mkfifo to stream data

So, fastq-dump has the ability to be run on just an SRA file accession number, such that the SRA is converted to FASTQ on-the-fly, and the SRA doesn't have to be written to disk. I'm curious whether ...
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2answers
138 views

Counting the number of hydrogen bonds of multiple PDB files

I've been trying to figure out a systematic way to count the number of hydrogen bonds for multiple PDB files. DSSP shows me the total number of hydrogen bonds when I make ...
4
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1answer
102 views

Publicly available resources for learning metagenomics

We are starting a metagenomics project in our research group to study microbiota in the respiratory tract. Since the are no books yet about metagenomics, seems reading some reviews and online ...
2
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1answer
187 views

what the best E-value cutoff in the miRNA homology search

I'm trying to use miRBase database to annotate some microRNA sequences in length 22-24bp. I highly appreciate if someone let me know whether I should do this BLAST against mature miRNA or stem-loop ...
6
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1answer
311 views

Find protein homologs with BLASTp

I'm trying to find homologs of a set of proteins using BLASTp. I'm working with custom databases. I'm using evalue of 0.00001 as threshold. I would like to filter queries having hits with >90% ...
3
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1answer
35 views

Gene Sequencing and Plasmapper

Is there anything similar to this in Java (especially the circular map sequencing along with hover effect)? For information I would like to convey that I am using Plasmapper and BioJava for achieving ...
2
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2answers
126 views

Local BLAST Copy Number per Hit

I generated a series of local BLAST databases using makeblastdb of metagenomic data and am searching for the presence of a particular gene. While I can do the normal BLAST analysis looking at ...
3
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1answer
91 views

What information can Uniprot give me about phosphorylated forms of proteins?

I have a list of proteins formatted like this: ...
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1answer
59 views

Why the name coined for MARKUP LANGUAGE for SBML? [closed]

I'm get the confusion about SYSTEM BIOLOGY filed. SBML is refer to as SYSTEM BIOLOGY MARKUP LANGUAGE why we should called as ...
3
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1answer
678 views

Why is Cysteine and Tyrosine used to calculate a sequence isoelectric point?

Why are the amino acids - cysteine and tyrosine used in isoelectric point calculations for a protein sequence, yet neither of them are positively charged molecules? and are not used in net charge ...
3
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1answer
1k views

Hamming distance between two DNA strings

By definition from Wikipedia, the Hamming distance between two strings of equal length is the number of positions at which the corresponding symbols are different. In other words, it is the number of ...
2
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1answer
68 views

Sequencing a specific region of a genome

First off, I'm new to bioinformatics and I am learning about DNA sequencing. Let's say that I knew that a specific region of a genome which contained information about a disease (whether it a person ...
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2answers
1k views

How to find miRNA binding sites on a specific gene?

I am trying to find miRNAs that bind to the 3'UTR of a specific gene. What is the best way of doing that (that is, with a good scoring analysis that is most commonly used by researchers in this area)? ...