Biology:Arginine kinase

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Short description: Class of enzymes
arginine kinase
Identifiers
EC number2.7.3.3
CAS number9026-70-4
Databases
IntEnzIntEnz view
BRENDABRENDA entry
ExPASyNiceZyme view
KEGGKEGG entry
MetaCycmetabolic pathway
PRIAMprofile
PDB structuresRCSB PDB PDBe PDBsum
Gene OntologyAmiGO / QuickGO

In enzymology, arginine kinase (EC 2.7.3.3) is an enzyme that catalyzes the chemical reaction

ATP + L-arginine [math]\displaystyle{ \rightleftharpoons }[/math] ADP + Nω-phospho-L-arginine

Thus, the two substrates of this enzyme are ATP and L-arginine, whereas its two products are ADP and Nω-phospho-L-arginine. Unlike the phosphoester bond, formed during the phosphorylation of serine, threonine or tyrosine residues, the phosphoramidate (P-N bond) in phospho-arginine is unstable at low pH (<8), making it difficult to detect with the traditional mass spectrometry protocols.[1]

Arginine kinase belongs to the family of transferases, specifically those transferring phosphorus-containing groups (phosphotransferases) with a nitrogenous group as acceptor. This enzyme participates in arginine and proline metabolism.

Nomenclature

The systematic name of this enzyme class is

  • ATP:L-arginine Nω-phosphotransferase

Other names in common use include

  • arginine phosphokinase,
  • adenosine 5'-triphosphate: L-arginine phosphotransferase,
  • adenosine 5'-triphosphate-arginine phosphotransferase,
  • ATP:L-arginine N-phosphotransferasel ATP:L-arginine, and
  • ω-N-phosphotransferase.

Function

In Gram-positive bacteria, such as Bacillus subtilis, the arginine kinase McsB phosphorylates the arginine residues on incorrectly folded or aggregated proteins to target them for degradation by the bacterial protease ClpC-ClpP (ClpCP).The phospho-arginine (pArg) modification is recognised by the N-terminal domain of ClpC, the protein-unfolding subunit of the ClpCP protease. Following recognition, the target protein is degraded by the ClpP subunit which has protease activity. Since phosphorylation reverses arginine's charge, the pArg modification has an unfolding effect on the target protein, easing its proteolytic degradation. Arginine phosphorylation is a dynamic post-translational modification, which can also be reversed by pArg-specific phosphatases, such as the bacterial YwlE. The pArg-ClpCP mechanism for protein degradation in bacteria is analogous to the eukaryotic ubiquitin-proteasome system.[2]

Several studies have reported the presence of arginine kinases in eukaryotes.[3][4] A recent study identified arginine phosphorylation on 118 proteins in Jurkat cells, which were primarily proteins with DNA/RNA-binding activities.[5] The function of arginine phosphorylation in eukaryotes however is still unknown.

Structural studies

As of late 2007, 8 structures have been solved for this class of enzymes, with PDB accession codes 1BG0​, 1M15​, 1M80​, 1P50​, 1P52​, 1RL9​, 1SD0​, and 2J1Q​.

References

  1. "Global impact of protein arginine phosphorylation on the physiology of Bacillus subtilis". Proceedings of the National Academy of Sciences of the United States of America 109 (19): 7451–7456. May 2012. doi:10.1073/pnas.1117483109. PMID 22517742. Bibcode2012PNAS..109.7451E. 
  2. "Arginine phosphorylation marks proteins for degradation by a Clp protease". Nature 539 (7627): 48–53. November 2016. doi:10.1038/nature20122. PMID 27749819. Bibcode2016Natur.539...48T. 
  3. "Characterization of an arginine-specific protein kinase tightly bound to rat liver DNA". European Journal of Biochemistry 166 (3): 617–621. August 1987. doi:10.1111/j.1432-1033.1987.tb13558.x. PMID 3609029. 
  4. "Ca(2+)-calmodulin-dependent phosphorylation of arginine in histone 3 by a nuclear kinase from mouse leukemia cells". The Journal of Biological Chemistry 269 (4): 2722–2727. January 1994. doi:10.1016/s0021-9258(17)42003-5. PMID 8300603. 
  5. "Widespread arginine phosphorylation in human cells - a novel protein PTM revealed by mass spectrometry". Science China Chemistry 63 (3): 341–346. March 2020. doi:10.1007/s11426-019-9656-7. https://www.biorxiv.org/content/biorxiv/early/2019/08/05/725291.full.pdf. 

Further reading