Protein phosphorylation is a post-translational modification that affects protein activity through the addition of a phosphate moiety by protein kinases or phosphotransferases. It occurs in all life forms. In addition to Hanks kinases found also in eukaryotes, bacteria encode membrane histidine kinases that, with their cognate response regulator, constitute two-component systems and phosphotransferases that phosphorylate proteins involved in sugar utilization on histidine and cysteine residues. In addition, they encode BY-kinases and arginine kinases that phosphorylate protein specifically on tyrosine and arginine residues respectively. They also possess unusual bacterial protein kinases illustrated here by examples from Bacillus subtilis.

蛋白质磷酸化是一种翻译后修饰，通过蛋白激酶或磷酸转移酶添加磷酸部分来影响蛋白质活性。它发生在所有生命形式中。除了在真核生物中也发现的 Hanks 激酶之外，细菌还编码膜组氨酸激酶，这些膜组氨酸激酶与其同源反应调节剂构成双组分系统和磷酸转移酶，它们磷酸化参与组氨酸和半胱氨酸残基上糖利用的蛋白质。此外，它们编码 BY 激酶和精氨酸激酶，分别在酪氨酸和精氨酸残基上特异性磷酸化蛋白质。它们还具有不寻常的细菌蛋白激酶，此处通过来自枯草芽孢杆菌的示例进行了说明。