title: Escherichia coli antitoxin MazE as transcription factor: insights into MazE-DNA binding.
abstract: Toxin-antitoxin (TA) modules are pairs of genes essential for bacterial regulation upon environmental stresses. The mazEF module encodes the MazF toxin and its cognate MazE antitoxin. The highly dynamic MazE possesses an N-terminal DNA binding domain through which it can negatively regulate its own promoter. Despite being one of the first TA systems studied, transcriptional regulation of Escherichia coli mazEF remains poorly understood. This paper presents the solution structure of C-terminal truncated E. coli MazE and a MazE-DNA model with a DNA palindrome sequence ∼ 10 bp upstream of the mazEF promoter. The work has led to a transcription regulator-DNA model, which has remained elusive thus far in the E. coli toxin-antitoxin family. Multiple complementary techniques including NMR, SAXS and ITC show that the long intrinsically disordered C-termini in MazE, required for MazF neutralization, does not affect the interactions between the antitoxin and its operator. Rather, the MazE C-terminus plays an important role in the MazF binding, which was found to increase the MazE affinity for the palindromic single site operator.
authors.affiliation: Molecular Recognition Unit, Structural Biology Research Center, VIB, Pleinlaan 2, 1050 Brussels, Belgium Structural Biology Brussels, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium.
authors.forename: Valentina
authors.initials: V
authors.lastname: Zorzini
authors.affiliation: Molecular Recognition Unit, Structural Biology Research Center, VIB, Pleinlaan 2, 1050 Brussels, Belgium Structural Biology Brussels, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium.
authors.forename: Lieven
authors.initials: L
authors.lastname: Buts
authors.affiliation: Institute of Chemistry/Organic and Bioorganic Chemistry, University of Graz, Heinrichstrasse 28, A-8010 Graz, Austria.
authors.forename: Evelyne
authors.initials: E
authors.lastname: Schrank
authors.affiliation: Molecular Recognition Unit, Structural Biology Research Center, VIB, Pleinlaan 2, 1050 Brussels, Belgium Structural Biology Brussels, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium.
authors.forename: Yann G J
authors.initials: YG
authors.lastname: Sterckx
authors.affiliation: Institute of Chemistry/Organic and Bioorganic Chemistry, University of Graz, Heinrichstrasse 28, A-8010 Graz, Austria.
authors.forename: Michal
authors.initials: M
authors.lastname: Respondek
authors.affiliation: Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada (IMRIC), The Hebrew University-Hadassah Medical School, Jerusalem 91120, Israel.
authors.forename: Hanna
authors.initials: H
authors.lastname: Engelberg-Kulka
authors.affiliation: Molecular Recognition Unit, Structural Biology Research Center, VIB, Pleinlaan 2, 1050 Brussels, Belgium Structural Biology Brussels, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium.
authors.forename: Remy
authors.initials: R
authors.lastname: Loris
authors.affiliation: Institute of Chemistry/Organic and Bioorganic Chemistry, University of Graz, Heinrichstrasse 28, A-8010 Graz, Austria.
authors.forename: Klaus
authors.initials: K
authors.lastname: Zangger
authors.affiliation: Molecular Recognition Unit, Structural Biology Research Center, VIB, Pleinlaan 2, 1050 Brussels, Belgium Structural Biology Brussels, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium nvnuland@vub.ac.be.
authors.forename: Nico A J
authors.initials: NA
authors.lastname: van Nuland
mesh_terms: D004269:DNA, Bacterial / Q000737:chemistry* / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000378:metabolism; D004722:Endoribonucleases / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000737:chemistry* / Q000378:metabolism; D055029:Inverted Repeat Sequences; D008958:Models, Molecular; D009875:Operator Regions, Genetic; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D014157:Transcription Factors / Q000737:chemistry* / Q000378:metabolism
chemical_list: D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; C422954:MazE protein, E coli; C422955:MazF protein, E coli; D014157:Transcription Factors; D004722:Endoribonucleases