xpt

xanthine phosphoribosyltransferase

Locus: BSU_22070

Isoelectric point: 5.84

Molecular weight: 20.89 kDa

Protein length: 194 aa

Gene length: 585 bp

Function: purine salvage and interconversion

Product: xanthine phosphoribosyltransferase

Essential: no

E.C.: 2.4.2.22

Synonyms

Genomic Context

Loading

Categories containing this gene/protein

• Metabolism → Nucleotide metabolism → Biosynthesis/ acquisition of nucleotides → Purine salvage and interconversion
• Information processing → Targets of second messengers → Targets of (p)ppGpp

Gene

Coordinates: 2,319,440 2,320,024

The protein

Catalyzed reaction/ biological activity

• 5-phospho-α-D-ribose 1-diphosphate + xanthine --> diphosphate + XMP (according to UniProt)

Protein family

• Purine/pyrimidine phosphoribosyltransferase family (according to UniProt)

Effectors of protein activity

• strongly inhibited by pGpp and ppGpp PubMed
• weakly inhibited by pppGpp PubMed

Structure

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

Localization

• cytoplasm (according to Swiss-Prot)

Additional information

• subject to Clp-dependent proteolysis upon glucose starvation PubMed

Expression and Regulation

Operons

• Genes: xpt-pbuX
  Description: PubMed

  Sigma factors

  • SigA: sigma factor, PubMed, in SigA regulon

  Regulatory mechanism

  • G-box: termination, riboswitch PubMed, in G-box
  • PurR: repression, (molecular inducer: PRPP) PubMed, in PurR regulon

  Regulation

  • induced in the absence of guanine (G-box) PubMed

Biological materials

Mutant

• MGNA-A870 (xpt::erm), available at the NBRP B. subtilis, Japan
• BKE22070 (xpt::erm trpC2) available at BGSC, PubMed, upstream reverse: _UP1_CATCCTGTCTACCTCCGTTA, downstream forward: _UP4_TCCTTCGTACAGGAGGTTCA
• BKK22070 (xpt::kan trpC2) available at BGSC, PubMed, upstream reverse: _UP1_CATCCTGTCTACCTCCGTTA, downstream forward: _UP4_TCCTTCGTACAGGAGGTTCA

LacZ fusion

• pGP430 (in pAC7), available in Jörg Stülke's lab

References

Loading