4NTQ

CdiA-CT/CdiI toxin and immunity complex from Enterobacter cloacae

Summary for 4NTQ

• Entry DOI: 10.2210/pdb4ntq/pdb
• Descriptor: Contact-dependent inhibitor A, ECL CdiI (3 entities in total)
• Functional Keywords: rnase, toxin, immunity
• Biological source: Enterobacter cloacae subsp. cloacae; More
• Total number of polymer chains: 2
• Total formula weight: 43346.57

Authors

Morse, R.P.,Goulding, C.W. (deposition date: 2013-12-02, release date: 2014-03-26, Last modification date: 2024-10-09)

Primary citation

Beck, C.M.,Morse, R.P.,Cunningham, D.A.,Iniguez, A.,Low, D.A.,Goulding, C.W.,Hayes, C.S.
CdiA from Enterobacter cloacae Delivers a Toxic Ribosomal RNase into Target Bacteria.
Structure, 22:1-12, 2014

PubMed Abstract: Contact-dependent growth inhibition (CDI) is one mechanism of inter-bacterial competition. CDI(+) cells export large CdiA effector proteins, which carry a variety of C-terminal toxin domains (CdiA-CT). CdiA-CT toxins are specifically neutralized by cognate CdiI immunity proteins to protect toxin-producing cells from autoinhibition. Here, we use structure determination to elucidate the activity of a CDI toxin from Enterobacter cloacae (ECL). The structure of CdiA-CT(ECL) resembles the C-terminal nuclease domain of colicin E3, which cleaves 16S ribosomal RNA to disrupt protein synthesis. In accord with this structural homology, we show that CdiA-CT(ECL) uses the same nuclease activity to inhibit bacterial growth. Surprisingly, although colicin E3 and CdiA(ECL) carry equivalent toxin domains, the corresponding immunity proteins are unrelated in sequence, structure, and toxin-binding site. Together, these findings reveal unexpected diversity among 16S rRNases and suggest that these nucleases are robust and versatile payloads for a variety of toxin-delivery platforms.

PubMed: 24657090
DOI: 10.1016/j.str.2014.02.012

Experimental method

X-RAY DIFFRACTION (2.4 Å)