Structures and functions of precursors of bacterial proteases

The data on the precursors of bacterial proteases were generalized. The str ucture and special features of processing of the precursors of bacillary su btilisins, the alpha -lytic protease from Lysobacter enzymogenes and the re lated chymotrypsin-like proteases from Streptomyces griseus, and the metall oproteases from bacilli and Pseudomonas aeruginosa were discussed. The appr oaches to producing the precursors and the protease propeptides and to in v itro characterizing them were particularly analyzed. The following physiolo gical functions of the propeptides within the protease precursors were cons idered probable: (a) inhibition of the proteases to protect the host cells from the proteolytic damage; (b) participation in the folding of the mature enzyme, and (c) providing for the protease interaction with the bacterial cell surveillance mechanisms. including protease translocation through the cell wall.