Expression post-translational modifications, 62, Table

EMBL Nucleotide Sequence Database. SWISS-PROT consists of core sequence data with minimal redundancy, citation and extensive annotations including protein function, post-translational modifications, domain sites, protein structural information, diseases associated with protein deficiencies and variants. SWISS-PROT and TrEMBL are available at EBI site, http //www.ebi.ac.uk/swissprot/, and ExPASy site, http //www.expasy.ch/sprot/. From the SWISS-PROT and TrEMBL page of ExPASy site, click Full text search (under Access to SWISS-PROT and TrEMBL) to open the search page (Figure 11.3). Enter the keyword string (use Boolean expression if required), check SWISS-PROT box, and click the Submit button. Select the desired entry from the returned list to view the annotated sequence data in Swiss-Prot format. An output in the fasta format can be requested. Links to BLAST, feature table, some ExPASy proteomic tools (e.g., Compute pI/Mw, ProtParam, ProfileScan, ProtScale, PeptideMass, ScanProsite), and structure (SWISS-MODEL) are provided on the page. 

Expressed proteins are often modified by post-translational processing, which may include cleavages at specific residues chemical modifications to the amino or carboxy terminus or to specific residues formation of disulfide bonds or the addition of phosphate, sulfete, fatty acyl groups, or carbohydrate. Chemical modifications may occur as well during sample isolation and preparation. When the sequence of the protein is known or can be inferred from the gene sequence, the type and location of specific modifications can often be deduced from simple mass differences between the expected and observed peaks in an enzymatic map. Thus, Table 10.4 shows a list of common modifications, their sites, and the mass differences that would be observed. 

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