Tunnel Formation Inferred from the I-Form Structures of the Proton-Driven Protein Secretion Motor SecDF

• Furukawa, Arata

• Yoshikaie, Kunihito

• Mori, Takaharu

• Mori, Hiroyuki

• Morimoto, Yusuke V

• Sugano, Yasunori

• Iwaki, Shigehiro

• Minamino, Tohru

• Sugita, Yuji

• Tanaka, Yoshiki

• Tsukazaki, Tomoya

Abstract

Protein secretion mediated by SecYEG translocon and SecA ATPase is enhanced by membrane-embedded SecDF by using proton motive force. A previous structural study of SecDF indicated that it comprises 12 transmembrane helices that can conduct protons and three periplasmic domains, which form at least two characterized transition states, termed the F and I forms. We report the structures of full-length SecDF in I form at 2.6- to 2.8-A resolution. The structures revealed that SecDF in I form can generate a tunnel that penetrates the transmembrane region and functions as a proton pathway regulated by a conserved Asp residue of the transmembrane region. In one crystal structure, periplasmic cavity interacts with a molecule, potentially polyethylene glycol, which may mimic a substrate peptide. This study provides structural insights into the Sec protein translocation that allows future analyses to develop a more detailed working model for SecDF.

Journal

• Cell Reports

  Cell Reports 19 (5), 895-901, 2017-05-02

  Cell Press

Keywords

• protein translocation
• Sec proteins
• membrane protein
• crystal structure
• SecYEG
• SecDF

Details

• CRID: 1050577309352789248
• NII Article ID: 120006226309
• NII Article ID: 120006353868
• ISSN: 22111247
• DOI: 10.1016/j.celrep.2017.04.030
• HANDLE: 10061/11714
• HANDLE: 2433/227558
• Web Site: https://naist.repo.nii.ac.jp/records/9171
• Web Site: https://api.elsevier.com/content/article/PII:S2211124717305247?httpAccept=text/xml
• Web Site: https://api.elsevier.com/content/article/PII:S2211124717305247?httpAccept=text/plain
• Text Lang: en
• Article Type: journal article
• Data Source:
  • IRDB
  • Crossref
  • CiNii Articles
  • KAKEN