Aim of this review is to explain bacterial persistence, toxin-antitoxin module and the way it works, protein translation and possible mechanisms of its inhibition and molecular mechanisms of bacterial persistence mediated by HipA. Baterial persistence is a dormant state in which bacteria tolerates many antibiotics and other stressful conditions. It is known that bacterial persistence promotes evolution of antibiotic resistence and it is the main cause of many chronic infections. In order to develop targeted therapy it is important to understand molecular mechanism by which bacteria become persistant. Genes which cause persistance are toxin-antitoxin modules. Toxin activation usually inhibits translation after which cell enters physiological state of slow growth and becomes persistant. If the toxin is inactivated then the cell restores its normal growth but is no longer persistant. First gene discovered in E. coli that causes persistance is hipA. It codes for serine/threonine kinase which inhibits translation, transcription and replication. Together with hipB (gene for anitoxin) is part od hipBA operon. The first model of persistence mediated by HipA suggested that HipA inhibits translation by phosphorylating EF-Tu, the elongation factor which brings charged tRNA molecules to the ribosome. However, in vitro experiments in which they used γ[32P]ATP results did not confirm the initial model. The further experimental work revealed that HipA phosphorylates glutamyl-tRNA-synthetase (GltX) which results in translation inhibition and activation of the enzyme RelA which produces (p)ppGpp. Finally, the results showed that phosphorylation depends on conformation of GltX. HipA always phosphorylates on Ser239 which is part of a conserved flexible loop that changes conformation when tRNAGlu binds and Ser239 becomes more exposed.