5MS0

pseudo-atomic model of the RNA polymerase lambda-based antitermination complex solved by cryo-EM

Summary for 5MS0

• Entry DOI: 10.2210/pdb5ms0/pdb
• EMDB information: 3561
• Descriptor: Antitermination protein N, DNAII, Transcription antitermination protein NusB, ... (15 entities in total)
• Functional Keywords: transcription/dna/rna, dna-dependent rna polymerase, bacterial transcription, ternary elongation complex, antitermination, transcription-dna-rna complex
• Biological source: Escherichia phage lambda (Bacteriophage lambda); More
• Total number of polymer chains: 14
• Total formula weight: 537670.38

Authors

Said, N.,Krupp, F. (deposition date: 2016-12-29, release date: 2017-05-03, Last modification date: 2024-05-15)

Primary citation

Said, N.,Krupp, F.,Anedchenko, E.,Santos, K.F.,Dybkov, O.,Huang, Y.H.,Lee, C.T.,Loll, B.,Behrmann, E.,Burger, J.,Mielke, T.,Loerke, J.,Urlaub, H.,Spahn, C.M.T.,Weber, G.,Wahl, M.C.
Structural basis for lambda N-dependent processive transcription antitermination.
Nat Microbiol, 2:17062-17062, 2017

PubMed Abstract: λN-mediated processive antitermination constitutes a paradigmatic transcription regulatory event, during which phage protein λN, host factors NusA, NusB, NusE and NusG, and an RNA nut site render elongating RNA polymerase termination-resistant. The structural basis of the process has so far remained elusive. Here we describe a crystal structure of a λN-NusA-NusB-NusE-nut site complex and an electron cryo-microscopic structure of a complete transcription antitermination complex, comprising RNA polymerase, DNA, nut site RNA, all Nus factors and λN, validated by crosslinking/mass spectrometry. Due to intrinsic disorder, λN can act as a multiprotein/RNA interaction hub, which, together with nut site RNA, arranges NusA, NusB and NusE into a triangular complex. This complex docks via the NusA N-terminal domain and the λN C-terminus next to the RNA exit channel on RNA polymerase. Based on the structures, comparative crosslinking analyses and structure-guided mutagenesis, we hypothesize that λN mounts a multipronged strategy to reprogram the transcriptional machinery, which may include (1) the λN C terminus clamping the RNA exit channel, thus stabilizing the DNA:RNA hybrid; (2) repositioning of NusA and RNAP elements, thus redirecting nascent RNA and sequestering the upstream branch of a terminator hairpin; and (3) hindering RNA engagement of termination factor ρ and/or obstructing ρ translocation on the transcript.

PubMed: 28452979
DOI: 10.1038/nmicrobiol.2017.62

Experimental method

ELECTRON MICROSCOPY (9.8 Å)