ABSTRACT
PhosphoBase contains information about phosphorylated residues in proteins and data about peptide phosphorylation by a variety of protein kinases. The data are collected from literature and compiled into a common format. The current release of PhosphoBase (October 1998, version 2.0) comprises 414 phosphoprotein entries covering 1052 phosphorylatable serine, threonine and tyrosine residues. The kinetic data from peptide phosphorylation assays for approximately 330 oligopeptides is also included. The database entries are cross-referenced to the corresponding records in the Swiss-Prot protein database and literature references are linked to MedLine records. PhosphoBase is available via the WWW at http://www.cbs.dtu. dk/databases/PhosphoBase/
Subject(s)
Databases, Factual , Phosphoproteins/chemistry , Protein Kinases/metabolism , Animals , Bacteria/chemistry , Humans , Internet , Kinetics , Phosphoproteins/metabolism , Phosphorylation , Phosphoserine , Phosphothreonine , Phosphotyrosine , Plants/chemistry , Substrate Specificity , Viruses/chemistryABSTRACT
The site and sequence specificity of protein kinases, as well as the role of the secondary structure and surface accessibility of the phosphorylation sites on substrate proteins, was statistically analyzed. The experimental data were collected from the literature and are available on the World Wide Web at http://www.cbs.dtu.dk/databases/PhosphoBase/. The set of data involved 1008 phosphorylatable sites in 406 proteins, which were phosphorylated by 58 protein kinases. It was found that there exists almost absolute Ser/Thr or Tyr specificity, with rare exceptions. The sequence specificity determinants were less strict and were located between positions -4 and +4 relative to the phosphorylation site. Secondary structure and surface accessibility predictions revealed that most of the phosphorylation sites were located on the surface of the target proteins.
Subject(s)
Protein Kinases/metabolism , Amino Acids , Binding Sites , Mathematical Computing , Phosphorylation , Protein Structure, Secondary , Substrate SpecificityABSTRACT
PhosphoBase is a database of experimentally verified phosphorylation sites. Version 1.0 contains 156 entries and 398 experimentally determined phosphorylation sites. Entries are compiled and revised from the literature and from major protein sequence databases such as SwissProt and PIR. The entries provide information about the phosphoprotein and the exact position of its phosphorylation sites. Furthermore, part of the entries contain information about kinetic data obtained from enzyme assays on specific peptides. To illustrate the use of data extracted from PhosphoBase we present a sequence logo displaying the overall conservation of positions around serines phosphorylated by protein kinase A (PKA). PhosphoBase is available on the WWW at http://www.cbs.dtu.dk/databases/PhosphoBase/