Structural mechanism of transcription inhibition by lasso peptides microcin J25 and capistruin.

TitleStructural mechanism of transcription inhibition by lasso peptides microcin J25 and capistruin.
Publication TypeJournal Article
Year of Publication2019
AuthorsBraffman, NR, Piscotta, FJ, Hauver, J, Campbell, EA, A Link, J, Darst, SA
JournalProc Natl Acad Sci U S A
Volume116
Issue4
Pagination1273-1278
Date Published2019 Jan 22
ISSN1091-6490
Abstract

We report crystal structures of the antibacterial lasso peptides microcin J25 (MccJ25) and capistruin (Cap) bound to their natural enzymatic target, the bacterial RNA polymerase (RNAP). Both peptides bind within the RNAP secondary channel, through which NTP substrates enter the RNAP active site, and sterically block trigger-loop folding, which is essential for efficient catalysis by the RNAP. MccJ25 binds deep within the secondary channel in a manner expected to interfere with NTP substrate binding, explaining the partial competitive mechanism of inhibition with respect to NTPs found previously [Mukhopadhyay J, Sineva E, Knight J, Levy RM, Ebright RH (2004) Mol Cell 14:739-751]. The Cap binding determinant on RNAP overlaps, but is not identical to, that of MccJ25. Cap binds further from the RNAP active site and does not sterically interfere with NTP binding, and we show that Cap inhibition is partially noncompetitive with respect to NTPs. This work lays the groundwork for structure determination of other lasso peptides that target the bacterial RNAP and provides a structural foundation to guide lasso peptide antimicrobial engineering approaches.

DOI10.1073/pnas.1817352116
Alternate JournalProc. Natl. Acad. Sci. U.S.A.
PubMed ID30626643
PubMed Central IDPMC6347699
Grant ListS10 RR029205 / RR / NCRR NIH HHS / United States
P41 GM103403 / GM / NIGMS NIH HHS / United States
R35 GM118130 / GM / NIGMS NIH HHS / United States
S10 RR027037 / RR / NCRR NIH HHS / United States
R01 GM107036 / GM / NIGMS NIH HHS / United States