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-Structure paper
Title | Identification and architecture of a putative secretion tube across mycobacterial outer envelope. |
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Journal, issue, pages | Sci Adv, Vol. 7, Issue 34, Year 2021 |
Publish date | Aug 20, 2021 |
Authors | Xiaoying Cai / Lei Liu / Chunhong Qiu / Chongzheng Wen / Yao He / Yanxiang Cui / Siyu Li / Xuan Zhang / Longhua Zhang / Changlin Tian / Lijun Bi / Z Hong Zhou / Weimin Gong / |
PubMed Abstract | Tuberculosis-causing mycobacteria have thick cell-wall and capsule layers that are formed from complex structures. Protein secretion across these barriers depends on a specialized protein secretion ...Tuberculosis-causing mycobacteria have thick cell-wall and capsule layers that are formed from complex structures. Protein secretion across these barriers depends on a specialized protein secretion system, but none has been reported. We show that Rv3705c and its homologous MSMEG_6251 in are tube-forming proteins in the mycobacterial envelope (TiME). Crystallographic and cryo-EM structures of these two proteins show that both proteins form rotationally symmetric rings. Two layers of TiME rings pack together in a tail-to-tail manner into a ring-shaped complex, which, in turn, stacks together to form tubes. TiME was detected mainly in the cell wall and capsule. Knocking out the TiME gene markedly decreased the amount of secreted protein in the culture medium, and expression of this gene in knocked-out strain partially restored the level of secreted protein. Our structure and functional data thus suggest that TiME forms a protein transport tube across the mycobacterial outer envelope. |
External links | Sci Adv / PubMed:34417177 / PubMed Central |
Methods | EM (single particle) / X-ray diffraction |
Resolution | 1.55 - 6.2 Å |
Structure data | EMDB-22705: EMDB-22706: PDB-7cu8: PDB-7cu9: |
Chemicals | ChemComp-SO4: ChemComp-MG: ChemComp-GOL: ChemComp-HOH: |
Source |
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Keywords | PROTEIN TRANSPORT / tubular protein / envelope-spanning channel / potential drug target |