FEATURES

DESCRIPTION

Also known as DOC_BPP1, doc. Toxic component of a type II toxin-antitoxin (TA) system (PubMed:18398006, PubMed:24141193). Phosphorylates EF-Tu on 'Thr-383' in vitro; can use ATP or GTP (PubMed:24141193). Also dephosphorylates in the presence of ADP or GDP. Can only phosphorylate before the ternary aminoacyl-tRNA EF-Tu-GTP complex is formed; interaction with cognate antitoxin phd prevents phosphorylation and dephosphorylation of EF-Tu. 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 (PubMed:18398006). 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 (PubMed:8411153). Overexpression of doc can induce the mRNA interferase activity of host RelE in vivo (PubMed:18757857)., 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. Interacts with cognate antitoxin phd, the exact ratio of doc:phd varies from 1:1 to 1:3. Interaction with phd prevents kinase or phosphorylase activity on EF-Tu. Interacts with the 30S ribosomal subunit.

EXTERNAL LINKS

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Protein kinase doc

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Molecular Synopsis