---
OA_place: publisher
OA_type: hybrid
_id: '22148'
abstract:
- lang: eng
  text: 'How the twin-arginine translocase (Tat) system transports fully folded substrate
    proteins across cellular membranes without disrupting membrane integrity has been
    a fundamental question in cell biology for decades. The Tat system, found in prokaryotes
    and plant organelles, recognizes a cargo signal peptide via a conserved twin-arginine
    motif. The multi-subunit Tat complex facilitates the proton-motive-force-dependent
    translocation process, yet its overall architecture has remained unknown. Here,
    we present the cryo-electron microscopy (cryo-EM) structure of the Escherichia
    coli (E. coli) trimeric TatB₃C₃ complex with bound substrate SufI, assembled in
    vivo. The complex adopts an unusual, wide-open, bowl-shaped architecture with
    a polar inner cavity. Unexpectedly, the cargo is engaged in a dual-contact mode:
    while the signal peptide binds inside one TatBC unit, the folded domain docks
    tightly onto an adjacent unit, possibly performing a proofreading function. This
    structure provides a mechanistic framework for substrate engagement and suggests
    the direct involvement of the entire Tat complex in substrate translocation.'
acknowledged_ssus:
- _id: EM-Fac
- _id: ScienComp
acknowledgement: We thank IST Austria for providing the funding. We thank IST Austria
  EM facility for the use of Titan Krios TEM. Data processing was performed using
  IST high-performance computer cluster. We thank Dr. R. Roemhild and Professor C.
  Guet (ISTA) for help in constructing Tat deletion strains and Dr. A. Charnagalov
  (ISTA) for technical help.
article_processing_charge: Yes (via OA deal)
article_type: original
author:
- first_name: Ziyu
  full_name: Zhao, Ziyu
  id: a63fe682-9f3a-11ee-bf8c-cfdf919b9850
  last_name: Zhao
- first_name: Leonid A
  full_name: Sazanov, Leonid A
  id: 338D39FE-F248-11E8-B48F-1D18A9856A87
  last_name: Sazanov
  orcid: 0000-0002-0977-7989
biorxivid: 1
citation:
  ama: Zhao Z, Sazanov LA. Structure of E. Coli twin-arginine translocase (Tat) complex
    with bound cargo. <i>Molecular Cell</i>. doi:<a href="https://doi.org/10.1016/j.molcel.2026.05.026">10.1016/j.molcel.2026.05.026</a>
  apa: Zhao, Z., &#38; Sazanov, L. A. (n.d.). Structure of E. Coli twin-arginine translocase
    (Tat) complex with bound cargo. <i>Molecular Cell</i>. Elsevier. <a href="https://doi.org/10.1016/j.molcel.2026.05.026">https://doi.org/10.1016/j.molcel.2026.05.026</a>
  chicago: Zhao, Ziyu, and Leonid A Sazanov. “Structure of E. Coli Twin-Arginine Translocase
    (Tat) Complex with Bound Cargo.” <i>Molecular Cell</i>. Elsevier, n.d. <a href="https://doi.org/10.1016/j.molcel.2026.05.026">https://doi.org/10.1016/j.molcel.2026.05.026</a>.
  ieee: Z. Zhao and L. A. Sazanov, “Structure of E. Coli twin-arginine translocase
    (Tat) complex with bound cargo,” <i>Molecular Cell</i>. Elsevier.
  ista: Zhao Z, Sazanov LA. Structure of E. Coli twin-arginine translocase (Tat) complex
    with bound cargo. Molecular Cell.
  mla: Zhao, Ziyu, and Leonid A. Sazanov. “Structure of E. Coli Twin-Arginine Translocase
    (Tat) Complex with Bound Cargo.” <i>Molecular Cell</i>, Elsevier, doi:<a href="https://doi.org/10.1016/j.molcel.2026.05.026">10.1016/j.molcel.2026.05.026</a>.
  short: Z. Zhao, L.A. Sazanov, Molecular Cell (n.d.).
corr_author: '1'
das_tickbox: '1'
dataavailabilitystatement: "This study did not generate new unique reagents. Strains
  and plasmids generated in this study are available from the lead contact without
  restrictions.\r\n• Source data are provided within this paper. The cryo-EM map is
  deposited in the Electron Microscopy Data Bank under accession number EMD-53848.
  The model is deposited in the Protein Data Bank under accession number 9R91. The
  structural data are publicly available as of the date of publication. Raw images
  of spot assays, SDS-PAGE and BN-PAGE gels with Coomassie staining and immunoblot
  images are available at Mendeley Data (https://doi.org/10.17632/v2g3p9n985.1).\r\n•
  This paper does not report original code.\r\n• Any additional information required
  to reanalyze the data reported in this paper is available from the lead contact
  upon request."
date_created: 2026-06-28T22:01:35Z
date_published: 2026-06-22T00:00:00Z
date_updated: 2026-06-29T12:55:19Z
day: '22'
ddc:
- '570'
department:
- _id: LeSa
doi: 10.1016/j.molcel.2026.05.026
external_id:
  biorxivid:
  - 10.1101/2025.09.16.676506
has_accepted_license: '1'
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://doi.org/10.1016/j.molcel.2026.05.026
month: '06'
oa: 1
oa_version: Published Version
publication: Molecular Cell
publication_identifier:
  eissn:
  - 1097-4164
  issn:
  - 1097-2765
publication_status: inpress
publisher: Elsevier
quality_controlled: '1'
related_material:
  record:
  - id: '22189'
    relation: research_data
    status: for_moderation
researchdata_availability: yes
scopus_import: '1'
status: public
supplementarymaterial: yes
title: Structure of E. Coli twin-arginine translocase (Tat) complex with bound cargo
tmp:
  image: /images/cc_by_nc.png
  legal_code_url: https://creativecommons.org/licenses/by-nc/4.0/legalcode
  name: Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0)
  short: CC BY-NC (4.0)
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
year: '2026'
...