tailieunhanh - Báo cáo khoa học: Classification of ATP-dependent proteases Lon and comparison of the active sites of their proteolytic domains

ATP-dependent Lon proteases belong to the superfamily of AAA + proteins. Until recently, the identity of the residues involved in their proteolytic active sites was not elucidated. However, the putative catalytic Ser–Lys dyad was recently suggested through sequence comparison of more than 100 Lon proteases from various sources. The presence of the catalytic dyadwas experimentally confirmedby site-directed mutagenesis of theEscherichia coliLon protease and by determination of the crystal structure of its proteolytic domain. Furthermore, this extensive sequence analysis allowed the definition of two subfamilies of Lon proteases, LonA and LonB, based on the consensus sequences in the active sites of their proteolytic domains. . | Eur. J. Biochem. 271 4865-4871 2004 FEBS 2004 doi Classification of ATP-dependent proteases Lon and comparison of the active sites of their proteolytic domains Tatyana V. Rotanova1 Edward E. Melnikov1 Anna G. Khalatova1 Oksana V. Makhovskaya1 Istvan Botos2 Alexander Wlodawer2 and Alla Gustchina2 1 Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry Russian Academy of Sciences Moscow Russia 2Macromolecular Crystallography Laboratory National Cancer Institute at Frederick MD USA ATP-dependent Lon proteases belong to the superfamily of AAA proteins. Until recently the identity of the residues involved in their proteolytic active sites was not elucidated. However the putative catalytic Ser-Lys dyad was recently suggested through sequence comparison of more than 100 Lon proteases from various sources. The presence of the catalytic dyad was experimentally confirmed by site-directed mutagenesis of the Escherichia coli Lon protease and by determination of the crystal structure of its proteolytic domain. Furthermore this extensive sequence analysis allowed the definition of two subfamilies of Lon proteases LonA and LonB based on the consensus sequences in the active sites of their proteolytic domains. These differences strictly associate with the specific characteristics of their AAA modules as well as with the presence or absence of an N-terminal domain. Keywords AAA proteins Lon proteases proteolytic site LonA and LonB subfamilies Ser-Lys dyad. ATP-dependent proteases assigned to the Lon family are key enzymes responsible for intracellular selective proteolysis which controls protein quality and maintains cellular homeostasis. These enzymes eliminate mutant and abnormal proteins and play an important role in the rapid turnover of short-lived regulatory proteins 1-5 . Lon proteases are conserved in prokaryotes and in eukaryotic organelles such as mitochondria. Lon and all other known ATP-dependent proteases FtsH ClpAP ClpXP and HslVU .