5LM7

Crystal structure of the lambda N-Nus factor complex

Summary for 5LM7

• Entry DOI: 10.2210/pdb5lm7/pdb
• Descriptor: Transcription termination/antitermination protein NusA, N utilization substance protein B homolog, 30S ribosomal protein S10, ... (5 entities in total)
• Functional Keywords: transcription regulation antitermination nus proteins phage lambda n protein, transcription
• Biological source: Escherichia coli O157:H7; More
• Cellular location: Cytoplasm : P0AFF8
• Total number of polymer chains: 10
• Total formula weight: 191050.77

Authors

Said, N.,Santos, K.,Weber, G.,Wahl, M.C. (deposition date: 2016-07-29, release date: 2017-04-05, Last modification date: 2024-01-10)

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

X-RAY DIFFRACTION (3.35 Å)