Using modern proteomic assays, we have identified the products of gene expression and posttranslational modifications of proteins of the bacterium Mycoplasma gallisepticum S6. Combinations of different technologies of protein separation by electrophoresis and mass-spectrometric analysis gave us a total of 446 proteins, i.e. 61% of the annotated proteins of this microorganism. The Pro-Q Diamond and Pro-Q Emerald dye technology was used for fluorescent detection of ten phosphoproteins and two glycoproteins. The acylation of proteins was studied by electrophoresis after in vivo labeling with different 14C-labeled fatty acids, followed by autoradiography. Sixteen acylated proteins were identified, with a quarter of them involved in plasma membrane construction and another quarter involved in cell energy metabolism.