BOL: Related items

Conserved Domain Database (CDD) version 3.11 released

Shikha Logwani — Wed, 19 Feb 2014 15:02:40 -0600

National Center for Biotechnology Information (NCBI) Conserved Domain Database (CDD) version 3.11 is now available with 596 new or updated NCBI-curated and 49,641 total domain models. The new version now contains the most recent Pfam release 27.

Updates to the Conserved Domain Database include:

Position-specific score matrices (PSSMs) have been recomputed for many models in CDD, and frequency tables have been added to the PSSMs;

The search databases distributed as part of this release can now be used with the more recent versions of RPS-BLAST (BLAST release 2.2.28 and up) using composition-based scoring. This abolishes the need to mask out compositionally biased regions in query sequences;

Domain annotation displays in CD-Search, BATCH CD-Search, and other services now all use a uniform display style. A new display option in CD-Search and BATCH CD-Search provides “standard” results, in addition to “concise” and “full” results. “Standard” results will provide, for each region on the query sequence, the best0-scoring domain model (if any) from each of CDD’s database providers (Pfam, SMART, COG, TIGRFAMs, Protein Clusters, and the NCBI in-house curation project), but will suppress redundancy from within a single provider's results list.

You can access CDD at the Conserved Domains homepage and find updated content on the CDD FTP site.

Reference:

NCBI Website

Sequence Viewer: Download Transcripts, Exons and Proteins

Mon, 15 Sep 2014 17:30:36 -0500

How to download FASTA sequence for certain gene features while in the NCBI's Sequence Viewer. Sequence Viewer homepage: www.ncbi.nlm.nih.gov/projects/sviewer/ Sequence Viewer playlist: https://www.youtube.com/playlist?list=PL76D7EE6A6A8AC1C3

HistoneDB 2.0 – with variants

Anjana — Fri, 03 Jun 2016 05:06:20 -0500

This histone database can be used to explore the diversity of histone proteins and their sequence variants in many organisms. The resource was established to better understand how sequence variation may affect functional and structural features of nucleosomes. To get started, select a histone type to explore its variants.

More at http://www.ncbi.nlm.nih.gov/projects/HistoneDB2.0/index.fcgi/browse/

Address of the bookmark: http://www.ncbi.nlm.nih.gov/projects/HistoneDB2.0/index.fcgi/browse/

Download assemblies from NCBI

Bulbul — Mon, 15 May 2017 06:02:32 -0500

A new “Download assemblies” button is now available in the Assembly database. This makes it easy to download data for multiple genomes without having to write scripts.

For example, you can run a search in Assembly and use check boxes (see left side of screenshot below) to refine the set of genome assemblies of interest. Then, just open the “Download assemblies” menu, choose the source database (GenBank or RefSeq), choose the file type, and start the download. An archive file will be saved to your computer that can be expanded into a folder containing your selected genome data files.

More at https://ncbiinsights.ncbi.nlm.nih.gov/2017/05/08/genome-data-download-made-easy/

NCBI to assist in Virus Hunting Data Science Hackathon

BioStar — Thu, 15 Nov 2018 12:55:01 -0600

NCBI Hackathon are pleased to announce the second installment of the SoCal Bioinformatics Hackathon. From January 9-11, 2019, the NCBI will help run a bioinformatics hackathon in Southern California hosted by the Computational Sciences Research Center at San Diego State University!

NCBI Hackathon specifically looking for folks who have experience in computational virus hunting or adjacent fields to identify known, taxonomically-definable and novel viruses from a few hundred thousand metagenomic datasets that we’ll put on cloud infrastructure. This event is for researchers, including students and postdocs, who are already engaged in the use of bioinformatics data or in the development of pipelines for virological analyses from high-throughput experiments. If this describes you, please apply! The event is open to anyone selected for the hackathon and willing to travel to SDSU (see below).

https://ncbiinsights.ncbi.nlm.nih.gov/2018/11/09/ncbi-sdsu-virus-hunting-data-science-hackathon-january-2019/

Blast on Docker, Google Cloud, Amazon Cloud

LEGE — Thu, 09 Jul 2020 02:57:11 -0500

As announced in a previous post, we offer a Docker version of NCBI BLAST+ that you can use locally or on the Google Cloud where we have pre-loaded BLAST databases. We are happy to announce that the same functionality is now available on the Amazon Cloud. In addition, we now offer 23 different BLAST databases on each cloud platform.

As mentioned before, working with BLAST+ in Docker and the cloud has several advantages:

Docker manages installation and maintenance of the BLAST programs and databases.
Docker makes it is easier to integrate BLAST with other tools in your pipelines.
NCBI BLAST databases are pre-loaded now on the both the Google Cloud and Amazon Cloud, providing fast access.

You can also use the BLAST+ Docker image on any Docker-enabled platform, such as another cloud platform or on your local computer.

See the BLAST+ in the Cloud and database information documentation to get started.

If you have any questions, please email us at blast-help@ncbi.nlm.nih.gov

Source:Dave Arndt

New Release of RefSeq !

Abhi — Tue, 16 Jul 2024 10:09:21 -0500

Check out RefSeq release 225, now available online and from the FTP site. You can access RefSeq data through NCBI Datasets.

What’s included in this release?

As of July 8, 2024, this full release incorporates genomic, transcript, and protein data containing:

448,507,905 records
334,845,613 proteins
63,542,774 RNAs
Sequences from 152,668 organisms

The release is provided in several directories as a complete dataset and also as divided by logical groupings.

A Beginner's Guide to Using Kraken for Taxonomic Classification

Neel — Fri, 13 Dec 2024 11:29:03 -0600

Kraken is a popular bioinformatics tool designed for fast and accurate taxonomic classification of metagenomic sequences. Its efficiency and precision make it a go-to resource for analyzing microbial communities, including bacteria, viruses, archaea, and fungi. Whether you're new to bioinformatics or experienced in the field, Kraken is an indispensable tool for taxonomic analysis.

In this blog, we’ll walk through the basics of Kraken, from installation to running an analysis, and highlight its key features and applications.

What is Kraken?

Kraken is a sequence classification tool that assigns taxonomic labels to DNA sequences using exact k-mer matching. It uses a reference database of genomes, dividing sequences into k-mers and identifying matches in a computationally efficient way.

Key Features of Kraken

Speed: Kraken processes data much faster than alignment-based methods.
Accuracy: It uses a precise k-mer matching algorithm for high-resolution taxonomic assignments.
Scalability: It can handle large metagenomic datasets.
Custom Databases: You can build and use custom databases tailored to your research needs.

Installing Kraken

System Requirements
- A Unix-based operating system (Linux/macOS).
- Sufficient computational resources for database building (RAM and disk space).
Installation Steps
- Clone the Kraken repository from GitHub:
  
  git clone https://github.com/DerrickWood/kraken.git cd kraken
- Compile the Kraken binaries:
  
  make
- Add Kraken to your PATH for easy access:
  
  export PATH=$PATH:/path/to/kraken

Preparing a Database

Kraken requires a database of reference genomes. You can use a pre-built database or create a custom one.

Downloading a Pre-built Database
Kraken offers pre-built databases, such as the MiniKraken database, which is lightweight and suitable for smaller datasets. Download it using:

kraken-build --download-library minikraken
Building a Custom Database
To include specific genomes, download FASTA files and build the database:

kraken-build --download-library bacteria --threads 4 --db my_database kraken-build --build --db my_database

This process may take considerable time and resources, depending on the size of the database.

Running Kraken

Once the database is ready, you can classify sequences.

Basic Usage
Use the following command to classify sequences:

kraken --db my_database --threads 4 --fastq-input input_sequences.fastq --output kraken_output.txt

Key options:
- --db: Specifies the database.
- --threads: Number of threads for parallel processing.
- --fastq-input: Indicates input file format (FASTQ/FASTA).
Interpreting Results
Kraken generates an output file with columns for sequence IDs, taxonomic classifications, and the confidence score.

Visualizing Kraken Results

Kraken results can be visualized using tools like Krona or converted to human-readable reports using kraken-report.

Generate a Report

kraken-report --db my_database kraken_output.txt > kraken_report.txt
Krona Visualization
Install Krona and convert Kraken output for visualization:

cut -f2,3 kraken_output.txt | ktImportTaxonomy -o krona_output.html

Open the HTML file in your browser to interactively explore the taxonomic classifications.

Advanced Usage

Confidence Thresholds
Adjust the confidence threshold for classification using the --confidence option. Higher values reduce false positives but may miss some true positives:

kraken --db my_database --confidence 0.1 --fastq-input input.fastq
Paired-End Reads
For paired-end sequencing data, use:

kraken --db my_database --paired reads_1.fastq reads_2.fastq
Customizing K-mers
Kraken allows you to set custom k-mer lengths during database building for specific applications.

Applications of Kraken

Microbial Ecology: Characterizing microbial communities in soil, water, and the human microbiome.
Pathogen Detection: Identifying pathogens in clinical samples.
Fungal Research: Analyzing fungal diversity in metagenomic datasets.
Environmental Monitoring: Tracking microbial populations in diverse habitats.

Conclusion

Kraken is a versatile and efficient tool for taxonomic classification in metagenomics. Its speed, accuracy, and flexibility make it a favorite among bioinformaticians. By following this guide, you can set up and use Kraken to unlock insights into microbial and fungal communities, paving the way for discoveries in ecology, medicine, and biotechnology.

ncbi-datasets-cli -- Quickstart: command line tools !

Jit — Tue, 07 Dec 2021 02:51:26 -0600

Install and use the NCBI Datasets command line tools

The NCBI Datasets datasets command line tools are datasets and dataformat .

Use datasets to download biological sequence data across all domains of life from NCBI.

Use dataformat to convert metadata from JSON Lines format to other formats.

Conda download:

https://anaconda.org/conda-forge/ncbi-datasets-cli

Buld Download

https://www.ncbi.nlm.nih.gov/datasets/builder/?tax_id=29979

Address of the bookmark: https://www.ncbi.nlm.nih.gov/datasets/docs/v1/quickstarts/command-line-tools/

Update Genome Workbench 2.7.15 released

Surabhi Chaudhary — Wed, 26 Feb 2014 16:12:17 -0600

NCBI Genome Workbench is an integrated application for viewing and analyzing sequence data. With Genome Workbench, you can view data in publically available sequence databases at NCBI, and mix this data with your own private data.

Genome Workbench can display sequence data in many ways, including graphical sequence views, various alignment views, phylogenetic tree views, and tabular views of data. It can also align your private data to data in public databases, display your data in the context of public data, and retrieve BLAST results.

Genome Workbench is built on the NCBI C++ ToolKit and uses cross-platform APIs for graphics. It runs on your local machine, and is available for Windows 2000/XP, Linux, MacOS X, and various flavors of Unix.

NCBI Genome Workbench is an integrated application for viewing and analyzing sequence data. Genome Workbench was developed entirely in-house at NCBI and makes use of the NCBI C++ ToolKit. The C++ ToolKit provides a convenient and flexible cross-platform API for managing system internals, database connections, network sockets, and the NCBI data model. In addition, the C++ ToolKit provides the Object Manager, which abstracts handling of sequences and sequence-related objects.

New Features in Genome Workbench 2.7.15

Multiple Alignment View: implemented adaptive feature display when zooming in
Active Objects Inspector replaces Selection Inspector. New View should offer an improved selection context examination. See Using Active Objects Inspector tutorial for more details.
Binary packages for Linux OpenSUSE 13.1 are now available

Bug Fixes and Improvements in Genome Workbench 2.7.15

Fixed major issue with OpenGL overlay/scrolling. Could cause crashes or view scrolling irregularities
Multiple Pane View: fixed crash on loading BLAST results
Graphical Sequence View: fixed crash on zooming in and out, related to SNP track
Graphical Sequence View: fixed Go To Position dialog to give better diagnostics in case of a user error
Graphical Sequence View: PDF export fixed rendering of Markers with commas in the name
Text View / Flat File: fixed Mac OS rendering issues
Text View / Flat File: performance optimization, extended capabilities of real-time rendering of molecules to tens of thousands
File Import: optimization improvement to speed up load of files containing multiple project items
File Import: remapping stage now shows accession.version and description of molecules, instead of plain GI numbers
Mac OS: improved tooltips for toolbar buttons
Phylogenetic Tree Builder Tool: improved diagnostics of errors
Multiple Alignment View: optimizations to avoid main GUI freezes
Open Dialog: removed duplicate elements in table of genomes (load Genome)
PDF export: fixed issue with XREF table errors
Tree View: fixed issues with showing Force Layout progress on Mac OS
Tree View: PDF export fixed issues for showing labels of collapsed nodes
Tree View: added an option to stop layout
Tree View: broadcasting mechanism fixed not to accumulate selected nodes

Reference:

NCBI news

http://www.ncbi.nlm.nih.gov/tools/gbench/