SURA is a PPIase enzyme and chaperone of Escherichia coli and other Gram-negative bacteria. SURA is a key player in the biogenesis of beta-barrel outer membrane proteins and is involved in cell envelope homeostasis and cell envelope functions. SURA is necessary for the survival of E. coli in stationary phase and needed for pilus biogenesis Synonyms: Rotamase surA, Survival protein A