Xpt

• Description: xanthine phosphoribosyltransferase
  
  

Gene name	xpt
Synonyms
Essential	no
Product	xanthine phosphoribosyltransferase
Function	purine salvage and interconversion
Gene expression levels in SubtiExpress: xpt
Metabolic function and regulation of this protein in SubtiPathways: xpt
MW, pI	20 kDa, 5.835
Gene length, protein length	582 bp, 194 aa
Immediate neighbours	pbuX, ypwA
Sequences	Protein DNA DNA_with_flanks
Genetic context This image was kindly provided by SubtiList
Expression at a glance   PubMed

Categories containing this gene/protein

biosynthesis/ acquisition of nucleotides, membrane proteins

This gene is a member of the following regulons

G-box, PurR regulon

The gene

Basic information

• Locus tag: BSU22070

Database entries

• BsubCyc: BSU22070

• DBTBS entry: [1]

• SubtiList entry: [2]

The protein

Basic information/ Evolution

• Catalyzed reaction/ biological activity: XMP + diphosphate = 5-phospho-alpha-D-ribose 1-diphosphate + xanthine (according to Swiss-Prot)

• Protein family:

• Paralogous protein(s):

Extended information on the protein

• Kinetic information:

• Domains:

• Modification:

• Cofactor(s):

• Effectors of protein activity:

• Interactions:

• Localization:
  • cell membrane (according to Swiss-Prot)

Database entries

• BsubCyc: BSU22070

• Structure: 1Y0B, 2FXV (complex with GMP), 1Y27 (the riboswitch in complex with guanine)

• UniProt: P42085

• KEGG entry: [3]

• E.C. number: 2.4.2.22

Additional information

• subject to Clp-dependent proteolysis upon glucose starvation PubMed

Expression and regulation

• Operon: xpt-pbuX PubMed

• Expression browser: xpt PubMed

• Sigma factor: SigA PubMed

• Regulation:
  • repressed in the presence of adenine or adenosine (PurR) PubMed
  • induced in the absence of guanine (G-box) PubMed

• Regulatory mechanism:
  • G-box: transcription termination/ antitermination (riboswitch) PubMed
  • PurR: transcription repression (molecular inducer: PRPP) PubMed

• Additional information: subject to Clp-dependent proteolysis upon glucose starvation PubMed
  • number of protein molecules per cell (minimal medium with glucose and ammonium): 2789 PubMed
  • number of protein molecules per cell (complex medium with amino acids, without glucose): 5194 PubMed

Biological materials

• Mutant:

• Expression vector:

• lacZ fusion: pGP430 (in pAC7), available in Stülke lab

• GFP fusion:

• two-hybrid system:

• Antibody: