The S4 domain is a small domain consisting of 60-65 amino acid residues that was detected in the bacterial ribosomal protein S4, eukaryotic ribosomal S9, two families of pseudouridine synthases, a novel family of predicted RNA methylases, a yeast pro ...
The S4 domain is a small domain consisting of 60-65 amino acid residues that was detected in the bacterial ribosomal protein S4, eukaryotic ribosomal S9, two families of pseudouridine synthases, a novel family of predicted RNA methylases, a yeast protein containing a pseudouridine synthetase and a deaminase domain, bacterial tyrosyl-tRNA synthetases, and a number of uncharacterized, small proteins that may be involved in translation regulation [1]. The S4 domain probably mediates binding to RNA.
This family contains a central domain Pfam:PF00013, hence the amino and carboxyl terminal domains are stored separately. This is a minimal carboxyl-terminal domain. Some are much longer.
YoeB-like toxin of bacterial type II toxin-antitoxin system
YoeB_toxin is a family of bacterial toxins that forms one component of the type II toxin-antitoxin system in E. coli whose antitoxin is represented by YefM, found in Pfam:PF02604. The plasmid encoded Axe-Txe proteins in Enterococcus faecium act as a ...
YoeB_toxin is a family of bacterial toxins that forms one component of the type II toxin-antitoxin system in E. coli whose antitoxin is represented by YefM, found in Pfam:PF02604. The plasmid encoded Axe-Txe proteins in Enterococcus faecium act as an antitoxin-toxin pair. When the plasmid is lost, the antitoxin is degraded relatively quickly by host enzymes. This allows the toxin to interact with its intracellular target, thus killing the cell or impeding cell growth [1]. These toxins are highly potent protein synthesis inhibitors, specifically blocking the initiation of translation. In the case of YoeB, it binds to the 50 S ribosomal subunit in 70 S ribosomes and interacts with the A site leading to mRNA cleavage at this site. As a result, the 3'-end portion of the mRNA is released from ribosomes, and translation initiation is effectively inhibited [2,3].