3dd7
Structure of DocH66Y in complex with the C-terminal domain of Phd
Structural highlights
FunctionDOC_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 PubMedProkaryotic toxin-antitoxin modules are involved in major physiological events set in motion under stress conditions. The toxin Doc (death on curing) from the phd/doc module on phage P1 hosts the C-terminal domain of its antitoxin partner Phd (prevents host death) through fold complementation. This Phd domain is intrinsically disordered in solution and folds into an alpha-helix upon binding to Doc. The details of the interactions reveal the molecular basis for the inhibitory action of the antitoxin. The complex resembles the Fic (filamentation induced by cAMP) proteins and suggests a possible evolutionary origin for the phd/doc operon. Doc induces growth arrest of Escherichia coli cells in a reversible manner, by targeting the protein synthesis machinery. Moreover, Doc activates the endogenous E. coli RelE mRNA interferase but does not require this or any other known chromosomal toxin-antitoxin locus for its action in vivo. Doc of prophage P1 is inhibited by its antitoxin partner Phd through fold complementation.,Garcia-Pino A, Christensen-Dalsgaard M, Wyns L, Yarmolinsky M, Magnuson RD, Gerdes K, Loris R J Biol Chem. 2008 Nov 7;283(45):30821-7. Epub 2008 Aug 30. PMID:18757857[5] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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