Structural characterization of the ABC transporter DppABCDF in Escherichia coli reveals insights into dipeptide acquisition.

ABSTRACT: The prokaryote-specific ATP-binding cassette (ABC) peptide transporters are involved in various physiological processes and plays an important role in transporting naturally occurring antibiotics across the membrane to their intracellular targets. The dipeptide transporter DppABCDF in Gram-negative bacteria is composed of five distinct subunits, yet its assembly and underlying peptide import mechanism remain elusive. Here, we report the cryo-EM structures of the DppBCDF translocator from Escherichia coli in both its apo form and in complexes bound to nonhydrolyzable or slowly hydrolyzable ATP analogs (AMPPNP and ATPγS), as well as the ATPγS-bound DppABCDF full transporter. Unlike the reported heterotrimeric Mycobacterium tuberculosis DppBCD translocator, the E. coli DppBCDF translocator is

SUBMITTER: Li P 

PROVIDER: S-EPMC12136057 | biostudies-literature | 2025 Mar

REPOSITORIES: biostudies-literature