B9LS20 · GUOP_HALLT
- ProteinGuanosine phosphorylase
- StatusUniProtKB reviewed (Swiss-Prot)
- Amino acids241 (go to sequence)
- Protein existenceEvidence at protein level
- Annotation score4/5
Function
function
Phosphorylase involved in the non-carboxylating pentose bisphosphate pathway, a nucleoside degradation pathway present in some halophilic archaea (PubMed:36434094).
Catalyzes the phosphorolytic cleavage of guanosine to guanine and ribose-1-phosphate (R1P) (PubMed:36434094).
Exhibits the highest activity toward guanosine, but also shows lower activity against inosine and adenosine (PubMed:36434094).
Catalyzes the phosphorolytic cleavage of guanosine to guanine and ribose-1-phosphate (R1P) (PubMed:36434094).
Exhibits the highest activity toward guanosine, but also shows lower activity against inosine and adenosine (PubMed:36434094).
Catalytic activity
- guanosine + phosphate = alpha-D-ribose 1-phosphate + guanineThis reaction proceeds in the forward direction.
Activity regulation
Activity is higher at low KCl concentrations.
Kinetics
KM | SUBSTRATE | pH | TEMPERATURE[C] | NOTES | EVIDENCE | |
---|---|---|---|---|---|---|
56 μM | guanosine | |||||
4.8 mM | phosphate |
Vmax | pH | TEMPERATURE[C] | NOTES | EVIDENCE | |
---|---|---|---|---|---|
1.5 μmol/min/mg | toward guanosine | ||||
2.1 μmol/min/mg | toward phosphate |
pH Dependence
Optimum pH is 7.5.
Temperature Dependence
Optimum temperature is 30 degrees Celsius.
GO annotations
Aspect | Term | |
---|---|---|
Cellular Component | cytosol | |
Molecular Function | guanosine phosphorylase activity | |
Molecular Function | S-methyl-5-thioadenosine phosphorylase activity | |
Biological Process | nucleoside catabolic process |
Keywords
- Molecular function
Enzyme and pathway databases
Names & Taxonomy
Protein names
- Recommended nameGuanosine phosphorylase
- EC number
Gene names
Organism names
- Strain
- Taxonomic lineageArchaea > Euryarchaeota > Stenosarchaea group > Halobacteria > Halobacteriales > Haloferacaceae > Halorubrum
Accessions
- Primary accessionB9LS20
Proteomes
Subcellular Location
UniProt Annotation
GO Annotation
PTM/Processing
Features
Showing features for chain.
Type | ID | Position(s) | Description | ||
---|---|---|---|---|---|
Chain | PRO_0000459712 | 1-241 | Guanosine phosphorylase | ||
Interaction
Protein-protein interaction databases
Structure
Sequence
- Sequence statusComplete
- Length241
- Mass (Da)25,738
- Last updated2009-03-24 v1
- Checksum437DEF34EF9D5A24
Keywords
- Technical term
Sequence databases
Nucleotide Sequence | Protein Sequence | Molecule Type | Status | |
---|---|---|---|---|
CP001365 EMBL· GenBank· DDBJ | ACM57894.1 EMBL· GenBank· DDBJ | Genomic DNA |