A novel family of toxin/antitoxin proteins in Bacillus species.
The C-terminal regions (CT) of Pfam PF04740 proteins share significant sequence identity with the toxic CdiA-CT effector domains of contact-dependent growth inhibition (CDI) systems. In accord with this homology, we find that several PF04740 CT domains inhibit cell growth when expressed in Escherichia coli. This growth inhibition is specifically blocked by antitoxin proteins encoded downstream of each PF04740 gene. The YobL-CT, YxiD-CT and YqcG-CT domains from Bacillus subtilis 168 have cytotoxic RNase activities, which are neutralized by the binding of cognate YobK, YxxD and YqcF antitoxin proteins, respectively. Our results show that PF04740 proteins represent a new family of toxin/antitoxin pairs that are widely distributed in Gram-positive bacteria.
Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, CA 93106-9625, USA.
Laura E
LE
Holberger
Fernando
F
Garza-Sánchez
James
J
Lamoureux
David A
DA
Low
Christopher S
CS
Hayes
D000595:Amino Acid Sequence; D000992:Antitoxins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D001407:Bacillus / Q000235:genetics* / Q000378:metabolism; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D001427:Bacterial Toxins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D005810:Multigene Family; D011485:Protein Binding; D054730:Protein Interaction Domains and Motifs / Q000502:physiology; D012260:Ribonucleases / Q000378:metabolism; D017386:Sequence Homology, Amino Acid
D000992:Antitoxins; D001426:Bacterial Proteins; D001427:Bacterial Toxins; D012260:Ribonucleases