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Structural characterization of the hypothetical protein Lpg2622, a new member of the C1 family peptidases from Legionella pneumophila
Author(s) -
Gong Xiaojian,
Zhao Xiaolei,
Zhang Wei,
Wang Jinzhao,
Chen Xiaofang,
Hameed Muhammad Fazal,
Zhang Nannan,
Ge Honghua
Publication year - 2018
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1002/1873-3468.13210
Subject(s) - legionella pneumophila , proteases , secretion , protein precursor , cysteine protease , effector , papain , protease , biochemistry , cysteine , protein family , chemistry , enzyme , microbiology and biotechnology , biology , bacteria , gene , genetics
The Legionella pneumophila type II secretion system can promote bacterial growth under a wide variety of conditions and mediates the secretion of more than 25 proteins, including the uncharacterized effector Lpg2622. Here, we determined the crystal structures of apo‐Lpg2622 and Lpg2622 in complex with the cysteine protease inhibitor E64. Structural analysis suggests that Lpg2622 belongs to the C1 family peptidases. Interestingly, unlike the other structurally resolved papain‐like cysteine proteases, the propeptide of Lpg2622 forms a novel super‐secondary structural fold (hairpin‐turn‐helix) and can be categorized into a new group. In addition, the N‐terminal β‐sheet of the Lpg2622 propeptide plays a regulatory role on enzymatic activity. This study enhances our understanding of the classification and regulatory mechanisms of the C1 family peptidases.