6GOX

SecA

Summary for 6GOX

• Entry DOI: 10.2210/pdb6gox/pdb
• Descriptor: Protein translocase subunit SecA (1 entity in total)
• Functional Keywords: truncation, protein transport
• Biological source: Escherichia coli K-12
• Total number of polymer chains: 1
• Total formula weight: 93351.03

Authors

White, S.A.,Huber, D. (deposition date: 2018-06-04, release date: 2019-06-19, Last modification date: 2024-05-15)

Primary citation

Jamshad, M.,Knowles, T.J.,White, S.A.,Ward, D.G.,Mohammed, F.,Rahman, K.F.,Wynne, M.,Hughes, G.W.,Kramer, G.,Bukau, B.,Huber, D.
The C-terminal tail of the bacterial translocation ATPase SecA modulates its activity.
Elife, 8:-, 2019

PubMed Abstract: In bacteria, the translocation of proteins across the cytoplasmic membrane by the Sec machinery requires the ATPase SecA. SecA binds ribosomes and recognises nascent substrate proteins, but the molecular mechanism of nascent substrate recognition is unknown. We investigated the role of the C-terminal tail (CTT) of SecA in nascent polypeptide recognition. The CTT consists of a flexible linker (FLD) and a small metal-binding domain (MBD). Phylogenetic analysis and ribosome binding experiments indicated that the MBD interacts with 70S ribosomes. Disruption of the MBD only or the entire CTT had opposing effects on ribosome binding, substrate-protein binding, ATPase activity and in vivo function, suggesting that the CTT influences the conformation of SecA. Site-specific crosslinking indicated that F399 in SecA contacts ribosomal protein uL29, and binding to nascent chains disrupts this interaction. Structural studies provided insight into the CTT-mediated conformational changes in SecA. Our results suggest a mechanism for nascent substrate protein recognition.

PubMed: 31246174
DOI: 10.7554/eLife.48385

Experimental method

X-RAY DIFFRACTION (3.5 Å)