||Human Homo sapiens
||Macek B. The serine/threonine/tyrosine phosphoproteome of the model bacterium Bacillus subtilis. Mol Cell Proteomics. 2007 Apr6(4):697-707 p.703 right column top paragraphPubMed ID17218307
||p.698 left column 3rd paragraph:"In this study [investigators] enzymatically digested the entire B. subtilis proteome and enriched phosphopeptides by titanium oxide chromatography (ref 42). Phosphopeptides were measured in a hybrid linear ion trap-Fourier transform ion cyclotron resonance or an orbitrap mass spectrometer, which determines their mass and fragmentation spectra. This gel-free approach has recently proven to be extremely powerful in studies of eukaryotic protein phosphorylation and allowed the determination of more than 6600 phosphorylation sites in HeLa cells (ref 43 see BNID 111946). Here [investigators] used this technology to obtain a site-specific, in vivo phosphoproteome of B. subtilis."
||p.703 left column bottom paragraph to right column top paragraph:"The dataset presented here is therefore the most comprehensive study of Ser/Thr/Tyr phosphorylation in a prokaryotic organism thus far and provides insight into the phosphoproteome of a model Gram-positive bacterium. A striking distinction to known metazoan phosphoproteomes is in its extent- whereas in humans more than 30% of proteins are phosphorylated, this and other studies (refs 17, 20) show that this number is at least an order of magnitude lower in bacteria."