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Structural insight into the E. coli HigBA complex.
- Source :
-
Biochemical & Biophysical Research Communications . Sep2016, Vol. 478 Issue 4, p1521-1527. 7p. - Publication Year :
- 2016
-
Abstract
- The toxin-antitoxin system is ubiquitously existed in bacteria and archaea, performing a wide variety of functions modulating cell fitness in response to environmental cues. In this report, we solved the crystal structure of the toxin-antitoxin HigBA complex from E. coli K-12 to 2.7 Å resolution. The crystal structure of the HigBA complex displays a hetero-tetramer (HigBA) 2 form comprised by two HigB and two HigA subunits. Each toxin HigB resumes a microbial RNase T1 fold, characteristic of a three antiparallel β-sheet core shielded by a few α-helices at either side. Each antitoxin HigA composed of all α-helices resembles a “C”-shaped clamp nicely encompassing a HigB in the (HigBA) 2 complex. Two HigA monomers dimerize at their N-terminal domain. We showed that HigA helix α1 was essential for HigA dimerization and the hetero-tetramer (HigBA) 2 formation, but not for a hetero-dimeric HigBA formation. HigA dimerization mediated by helix α1 was dispensable for DNA-binding, as a heterodimeric HigBA complex still bound to the higBA operator in vitro . The HigA C-terminal domain with a helix-turn-helix fold was essential for DNA binding. We also defined two palindromes in higBA operator specifically recognized by HigA and HigBA in vitro . [ABSTRACT FROM AUTHOR]
- Subjects :
- *ESCHERICHIA coli
*ANTITOXINS
*CRYSTAL structure
*RIBONUCLEASES
*MONOMERS
Subjects
Details
- Language :
- English
- ISSN :
- 0006291X
- Volume :
- 478
- Issue :
- 4
- Database :
- Academic Search Index
- Journal :
- Biochemical & Biophysical Research Communications
- Publication Type :
- Academic Journal
- Accession number :
- 118178113
- Full Text :
- https://doi.org/10.1016/j.bbrc.2016.08.131