Domain

Arginine repressor, C-terminal (IPR020899)

Short name: Arg_repress_C

Overlapping homologous superfamilies

Domain relationships

None.

Description

The arginine dihydrolase (AD) pathway is found in many prokaryotes and some primitive eukaryotes, an example of the latter being Giardia lamblia (Giardia intestinalis) [PMID: 9504342]. The three-enzyme anaerobic pathway breaks down L-arginine to form 1 mol of ATP, carbon dioxide and ammonia. In simpler bacteria, the first enzyme, arginine deiminase, can account for up to 10% of total cell protein [PMID: 9504342].

Most prokaryotic arginine deiminase pathways are under the control of a repressor gene, termed ArgR [PMID: 1583685]. This is a negative regulator, and will only release the arginine deiminase operon for expression in the presence of arginine [PMID: 9851988]. The crystal structure of apo-ArgR from Bacillus stearothermophilus has been determined to 2.5A by means of X-ray crystallography [PMID: 10331868]. The protein exists as a hexamer of identical subunits, and is shown to have six DNA-binding domains, clustered around a central oligomeric core when bound to arginine. It predominantly interacts with A.T residues in ARG boxes. This hexameric protein binds DNA at its N terminus to repress arginine biosyntheis or activate arginine catabolism. Some species have several ArgR paralogs. In a neighbour-joining tree, some of these paralogous sequences show long branches and differ significantly from the well-conserved C-terminal region.

The C-terminal domain of the arginine repressor is responsible for aginine binding and multimerisation [PMID: 11856827, PMID: 9334747].

GO terms

Biological Process

GO:0051259 protein complex oligomerization

Molecular Function

GO:0034618 arginine binding

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.
ProDom
Pfam