title: Crystallographic observation of the movement of the membrane-distal domain of the T7SS core component EccB1 from Mycobacterium tuberculosis.
abstract: The protein EccB1, a core component of the type VII secretion system (T7SS) of Mycobacterium tuberculosis, has been identified as an ATPase and is essential for the secretion of virulence factors by the ESX-1 system. In a previous study, EccB1 structures were determined in two different conformations. Here, two new conformations are identified and described. These four conformations present snapshots of the swinging movement of the membrane-distal domain A2. The movement of this domain involves conformational changes in two flexible loops (loop A, residues 243-264, and loop B, residues 324-341) which are rich in proline and glycine residues and connect domain A2 to domains C1 and B2. It is proposed that the movement of this domain is related to the ATPase activity of EccB1 and its homologues, as well as to the substrate transport of ESX secretion systems.
authors: School of Life Science, Wenzhou Medical University, Wenzhou 325035, People's Republic of China.
authors: Xiao-Qian
authors: XQ
authors: Xie
authors: Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, People's Republic of China.
authors: Xiao-Li
authors: XL
authors: Zhang
authors: Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, People's Republic of China.
authors: Chao
authors: C
authors: Qi
authors: Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, People's Republic of China.
authors: De-Feng
authors: DF
authors: Li
authors: Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, People's Republic of China.
authors: Joy
authors: J
authors: Fleming
authors: Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, People's Republic of China.
authors: Da-Cheng
authors: DC
authors: Wang
authors: School of Life Science, Wenzhou Medical University, Wenzhou 325035, People's Republic of China.
authors: Li-Jun
authors: LJ
authors: Bi
mesh_terms: D000251:Adenosine Triphosphatases / Q000737:chemistry / Q000378:metabolism*; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry* / Q000378:metabolism*; D058947:Bacterial Secretion Systems / Q000737:chemistry / Q000378:metabolism*; D003460:Crystallization / Q000379:methods*; D018360:Crystallography, X-Ray / Q000379:methods*; D008969:Molecular Sequence Data; D009169:Mycobacterium tuberculosis / Q000378:metabolism*; D011487:Protein Conformation; D017434:Protein Structure, Tertiary; D017386:Sequence Homology, Amino Acid
chemical_list: D001426:Bacterial Proteins; D058947:Bacterial Secretion Systems; D000251:Adenosine Triphosphatases
keywords: ESX-1; Mycobacterium tuberculosis; Rv3869; type VII secretion system