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Articles tagged: database manager
Downloading UniProt proteomes via new API
The UniProt website received a snazzy facelift in June 2022. Both the browser interface and the REST API were updated. The previous version, now termed legacy website, remains available until the 2022_04 release under a new URL (https://legacy.uniprot.org/) – so there is limited time to compare and admire the improvements! The new API is an almost seamless transition for Mascot [...]
NCBI nr in Mascot Server 2.8.1
Mascot Server 2.8.01 patch was released in March 2022. One of the big improvements is optimising the compression speed of the NCBI nr database, available as the NCBIprot predefined definition. We’ve greatly decreased the time it takes to bring the database online, as well as removed an inadvertent limitation on database size. The patch is available to download on the [...]
Retiring the File Transfer Protocol (FTP)
Mascot Server includes Database Manager, which can be configured to download protein sequence databases from many sources using FTP (File Transfer Protocol), HTTP (Hyper Text Transfer Protocol) and HTTPS (HTTP Secure). FTP is the oldest of these protocols by far, making its first appearance in 1971. Until some years ago, FTP was the best and only choice for large file [...]
NCBI nr tips
NCBI nr is the comprehensive database of non-identical protein sequences compiled by the National Center for Biotechnology Information. The database is available in Mascot Server as the NCBIprot predefined definition. If possible, nr should be used as the database of last resort due to its huge size. The January 2021 version contains 338 million protein sequences and the FASTA file [...]
NIST Human HCD Spectral Libraries
Mascot 2.6 and later can search spectral libraries using the MSPepSearch spectral library search engine from the US National Institute of Standards and Technology (NIST). Spectral libraries can be searched alongside FASTA sequence databases to give an integrated report, and you can easily generate spectral libraries from your own search results. When we introduced spectral library searches in Mascot 2.6, [...]
The minutiae of database management
The two major inputs into a database search are sequence databases and mass spectrometry data. Management of the databases in Mascot Server has evolved and improved over the years and newer versions. There are still a few issues that come up regularly and I am going to cover them in this article. Common error messages When you activate a new [...]
Is your database search reproducible?
A lot has been written about the reproducibility of shotgun proteomics workflows, as well as controlling measurement variability between instruments and laboratories. An equally important factor is data analysis transparency and reproducibility, which is gaining increasing visibility. This boils down to two essentials: recording all software parameters used, and ensuring the software produces the same output given the same input [...]
X!Hunter MGF libraries
Mascot 2.6 supports three file formats for spectral libraries: the NIST MSP format, the SpectraST sptxt format and the X!Hunter MGF format. The sptxt format is a variation on MSP and will be covered in a future blog post. The main functional difference between MSP and MGF is in the level of annotation. The X!Hunter MGF format is minimalistic and [...]
Don’t wait: use spectral libraries now
The Human Proteome Project 2018 special issue in the Journal of Proteome Research contains a report from the 2017 Dagstuhl Seminar on Computational Proteomics. The paper by Deutsch et al. is titled Expanding the Use of Spectral Libraries in Proteomics, and the authors identify several challenges that slow down spectral library adoption. I’d like to address their main points. Adoption [...]
Keeping genome databases up to date
Database Manager is a great tool for keeping your sequence databases up to date in Mascot. If the database is available as a ready-made FASTA file, all you need to do is enable it as a predefined definition, or set up a definition to download the file from a known URL (see the help for more details). Updating the database [...]