Protein Family Models

This family consists of several Enterobacterial post-segregation antitoxin CcdA proteins. The F plasmid-carried bacterial toxin, the CcdB protein, is known to act on DNA gyrase in two different ways. CcdB poisons the gyrase-DNA complex, blocking the passage of polymerases and leading to double-strand breakage of the DNA. Alternatively, in cells that overexpress CcdB, the A subunit of DNA gyrase (GyrA) has been found as an inactive complex with CcdB. Both poisoning and inactivation can be prevented and reversed in the presence of the F plasmid-encoded antidote, the CcdA protein [1]. [1]. 10196173. Interactions of CcdB with DNA gyrase. Inactivation of Gyra, poisoning of the gyrase-DNA complex, and the antidote action of CcdA. Bahassi EM, O'Dea MH, Allali N, Messens J, Gellert M, Couturier M;. J Biol Chem 1999;274:10936-10944. (from Pfam)

Date:

2024-10-16

type II toxin-antitoxin (TA) system antitoxin CcdA is the antitoxin component of the TA system that inhibits the post-segregational killing of plasmid-free cells; binds to and blocks the activity of the toxin CcdB

Date:

2019-12-02

Gene:

ccdA

Date:

2020-10-26