3dd9 | pdb_00003dd9
Structure of DocH66Y dimer
Structural highlights
Function[DOC_BPP1] Toxic component of a toxin-antitoxin (TA) module. Overexpression results in inhibition of growth in liquid cultures and a decrease in colony formation by inhibiting translation, stabilizing mRNA and polysomes; these effects are overcome by concomitant expression of antitoxin phd. Binds 70S ribosomes and the 30S ribosomal subunits, the binding site is the same as for the antibiotic hygromycin B. Bacteriophage P1 lysogenizes bacteria as a low-copy number plasmid. Doc and phd proteins function in unison to stabilize plasmid number by inducing a lethal response to P1 plasmid prophage loss. Overexpression of doc can induce the mRNA interferase activity of RelE in vivo.[1] [2] Antitoxin phd binds to its own promoter repressing its expression; toxin doc acts as a corepressor or derepressor depending on the ratio, repressing or inducing expression.[3] [4] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe toxin Doc from the phd/doc toxin-antitoxin module targets the cellular translation machinery and is inhibited by its antitoxin partner Phd. Here we show that Phd also functions as a chaperone, keeping Doc in an active, correctly folded conformation. In the absence of Phd, Doc exists in a relatively expanded state that is prone to dimerization through domain swapping with its active site loop acting as hinge region. The domain-swapped dimer is not capable of arresting protein synthesis in vitro, whereas the Doc monomer is. Upon binding to Phd, Doc becomes more compact and is secured in its monomeric state with a neutralized active site. The intrinsically disordered domain of the antitoxin Phd chaperones the toxin Doc against irreversible inactivation and misfolding.,De Gieter S, Konijnenberg A, Talavera A, Butterer A, Haesaerts S, De Greve H, Sobott F, Loris R, Garcia-Pino A J Biol Chem. 2014 Dec 5;289(49):34013-23. doi: 10.1074/jbc.M114.572396. Epub 2014, Oct 16. PMID:25326388[5] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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