Conserved Domain
Database Debuts with
RPS-BLAST Search
Interface
Enhanced Access to
Taxonomy Database
Catch the Gene
Expression Omnibus
A Pair of Pathogens
Added to GenBank
Protein Molecular
Weight Field
Now in Entrez
OMIM In Entrez:
New Searching Power
Web Server Software
Available for BLAST
PSI-BLAST 2.1
Offers Composition-
Based Statistics
Protein Molecular Weight Field Now in Entrez
A Molecular Weight search field for proteins is now available in Entrez. This data will be particularly useful to the mass spectrometry research community for which the mass of a protein provides the means of its identification.
As with the Length field in Entrez, the numerical search term must be 6 digits long and must be padded with leading zeros if necessary. For instance, the syntax below can be used to specify a range of molecular weights from 65,000 to 75,000:
065000:075000 [Molecular Weight]
By default, protein molecular weights included in Entrez are calculated for the whole protein, excluding initial methionine residues. However, if a signal peptide is annotated in the database record, the molecular weight is calculated for the remainder of the protein, after excluding the signal sequence. If cleavage products are annotated, a molecular weight is calculated for each individual cleavage product, rather than for the whole protein. Ambiguous amino acids are treated as one of their possible forms. Molecular weights are not computed for proteins containing unknown amino acids. —JO, DW
NCBI acknowledges Dr. Lewis Pannell for his help in developing parameters for protein molecular weight calculation.
