Send to

Choose Destination
FEBS Lett. 2007 May 1;581(9):1727-34. Epub 2007 Mar 30.

Identification and characterization of a novel toxin-antitoxin module from Bacillus anthracis.

Author information

School of Biotechnology, Jawaharlal Nehru University, New Delhi-110067, India.


Comparative genome analysis of Bacillus anthracis revealed a pair of linked genes encoding pemK (K, killer protein) and pemI (I, inhibitory protein) homologous to pem loci of other organisms. Expression of PemK in Escherichia coli and Bacillus anthracis was bacteriostatic whereas the concomitant expression of PemI reversed the growth arrest. PemK expression effectively inhibited protein synthesis with no significant effect on DNA replication. Coexpression and interaction of these proteins confirmed it to be a Type II addiction module. Thermal denaturation analysis reflected poor conformational stability of PemI as compared to PemK. Circular dichroism analysis indicated that PemI contains twice the amount of beta-sheets as PemK. Gel retardation assays demonstrated that PemI binds to its upstream DNA sequence. This study reports the first evidence of an active chromosome encoded toxin-antitoxin locus in B. anthracis.

[Indexed for MEDLINE]
Free full text

Supplemental Content

Full text links

Icon for Wiley
Loading ...
Support Center