This entry describes the N-terminal domain of ParB proteins, predominantly found in bacteria. This domain is characterised by a highly conserved arginine motif, RRXR, known as the arginine patch, which is crucial for ParB DNA binding activity [1-2]. ...
This entry describes the N-terminal domain of ParB proteins, predominantly found in bacteria. This domain is characterised by a highly conserved arginine motif, RRXR, known as the arginine patch, which is crucial for ParB DNA binding activity [1-2]. ParB plays a vital role in chromosome partitioning and nucleoid occlusion. These proteins are essential for ensuring proper chromosome segregation during cell division by binding to the DNA origin of replication and localising to both poles of the predivisional cell following DNA replication. ParB comprises three highly conserved domains: an N-terminal nucleotide-binding domain (NBD), a central helix-turn-helix (HTH) parS-binding domain, a non-structured linker region, and a C-terminal dimerisation domain that tightly links the two subunits of the ParB dimer [3]. ParB proteins share significant sequence and structural similarity with Sulfiredoxin (Srx), a sulfinic acid reductase identified in eukaryotes. Sequence comparison and phylogenetic analysis of the Srx and ParB protein families suggest that Srx evolved via truncation of ParB, resulting in the removal of the entire C-terminal half of the protein including the HTH domain [4].
This is the C-terminal domain of 1-Cys peroxiredoxin (1-cysPrx), a member of the peroxiredoxin superfamily which protect cells against membrane oxidation through glutathione (GSH)-dependent reduction of phospholipid hydroperoxides to corresponding al ...
This is the C-terminal domain of 1-Cys peroxiredoxin (1-cysPrx), a member of the peroxiredoxin superfamily which protect cells against membrane oxidation through glutathione (GSH)-dependent reduction of phospholipid hydroperoxides to corresponding alcohols [1]. The C-terminal domain is crucial for providing the extra cysteine necessary for dimerisation of the whole molecule. Loss of the enzyme's peroxidase activity is associated with oxidation of the catalytic cysteine, upstream of this domain; and glutathionylation, presumably through its disruption of protein structure, facilitates access for GSH, resulting in spontaneous reduction of the mixed disulfide to the sulfhydryl and consequent activation of the enzyme [2]. The domain is associated with family AhpC-TSA, Pfam:PF00578, which carries the catalytic cysteine.
