Skórko-Glonek J, Wawrzynów A, Krzewski K, Kurpierz K, Lipińska B
Department of Biochemistry, University of Gdańsk, Poland.
Gene. 1995 Sep 22;163(1):47-52. doi: 10.1016/0378-1119(95)00406-v.
The HtrA(DegP) 48-kDa serine protease of Escherichia coli is indispensable for bacterial survival at elevated temperatures. It contains the amino-acid sequence Gly208AnsSerGlyGlyAlaLeu, which is similar to the consensus sequence GlyAspSerGlyGlyProLys surrounding the active Ser residue of trypsin-like proteases. Mutational alteration of Ser210 eliminated proteolytic activity of HtrA. An identical effect was observed when His105 was mutated. The mutated HtrA were unable to suppress thermosensitivity of the htrA bacteria. These results suggest that Ser210 and His105 may be important elements of the catalytic domain and indicate that the proteolytic activity of HtrA is essential for the survival of cells at elevated temperatures.
大肠杆菌的HtrA（DegP）48 kDa丝氨酸蛋白酶对于细菌在高温下的存活至关重要。它包含氨基酸序列Gly208AnsSerGlyGlyAlaLeu，该序列与胰蛋白酶样蛋白酶活性丝氨酸残基周围的共有序列GlyAspSerGlyGlyProLys相似。Ser210的突变改变消除了HtrA的蛋白水解活性。当His105发生突变时，观察到相同的效果。突变的HtrA无法抑制htrA细菌的热敏感性。这些结果表明，Ser210和His105可能是催化结构域的重要元件，并表明HtrA的蛋白水解活性对于细胞在高温下的存活至关重要。
