Sulfolobus acidocaldarius phosphoproteome

Shotgun phosphoproteome of Sulfolobus acidocaldarius using PAciFIC technique. Briefly, proteins were denatured, alkylated, trypsine digestion, SCX separation Fractionated peptides were analysed on Bruker HCTultra. Data processing and bioinformatics: data from mass spectrometry were then extracted to mgf format using Bruker Data Analysis V4.0 with a MRM script, these were then were searched against the Sulfolobus acidocaldarius database (containing 2223 proteins) downloaded from NCBI in March 2010 using Phenyx V 2.6 (Genebio, Geneva). The searches were performed using parameters as follows: carbamidomethylation of cysteine (fixed modification), oxidation of methionine (variation), and phosphorylation of serine, tyrosine, threonine (variation), trypsin with 2 missed cleavages. Furthermore, other parameters such as parent, MS/MS, tolerances were set at 2.0 and 0.8 Da, respectively, whilst minimum peptide length, z-score, p-value and AC score were set at 5, 5.5, 10-5, and 5.5 respectively.