The Escherichia coli rnlAB operon encodes a toxin–antitoxin module that is
involved in protection against infection by bacteriophage T4. The full-length
RnlA–RnlB toxin–antitoxin complex as well as the toxin RnlA were purified to
homogeneity and crystallized. When the affinity tag is placed on RnlA, RnlB is
largely lost during purification and the resulting crystals exclusively comprise
RnlA. A homogeneous preparation of RnlA–RnlB containing stoichiometric
amounts of both proteins could only be obtained using a His tag placed
C-terminal to RnlB. Native mass spectrometry and SAXS indicate a 1:1
stoichiometry for this RnlA–RnlB complex. Crystals of the RnlA–RnlB
complex belonged to space group C2, with unit-cell parameters a = 243.32,
b = 133.58, c = 55.64 A ˚ , = 95.11, and diffracted to 2.6 A ˚ resolution. The
presence of both proteins in the crystals was confirmed and the asymmetric unit
is likely to contain a heterotetramer with RnlA2:RnlB2 stoichiometry.
Original languageEnglish
Pages (from-to)31-39
Number of pages9
JournalActa Crystallographica Section F - Structural Biology Communications
Publication statusPublished - Jan 2020

    Research areas

  • macromolecular complex, Toxin-antitoxin module, X-ray crystallography, Bacterial stress response

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