BipA (also called TypA) is a highly conserved protein with global regulatory properties in Escherichia coli. BipA is phosphorylated on a tyrosine residue under some cellular conditions. Mutants show altered regulation of some pathways. BipA functions as a translation factor that is required specifically for the expression of the transcriptional modulator Fis. BipA binds to ribosomes at a site that coincides with that of EF-G and has a GTPase activity that is sensitive to high GDP:GTP ratios and is stimulated by 70S ribosomes programmed with mRNA and aminoacylated tRNAs. The growth rate-dependent induction of BipA allows the efficient expression of Fis, thereby modulating a range of downstream processes, including DNA metabolism and type III secretion. The domain II of BipA shows similarity to the domain II of the elongation factors (EFs) EF-G and EF-Tu.