Genome Property Definition Page

Namexanthosine utilization system XapABR
DescriptionThe three components of this system are xanthosine phosphorylase (XapA), xanthosine permease (XapB), together in a two-gene operon, and a constituitively expressed LysR-family positive regulator XapR, whose gene is just downstream from the xapAB operon. An open reading frame about 50 codons in length, found between xapB and xapR in Escherichia coli, although not characterized, appears to be conserved in species with XapABR and to have homologs in other genomic contexts in more distantly related species. Analysis by PSI-BLAST showed this is a conserved domain (see TIGR03510), and we name this small protein XapX.
JCVI RoleOther
Parent PropertyGenProp0816: nucleoside catabolism/utilization pathways
Literature References
[ 1 ] Seeger C, Poulsen C, Dandanell G   Identification and characterization of genes (xapA, xapB, and xapR) involved in xanthosine catabolism in Escherichia coli.   J Bacteriol. 1995 Oct;177(19):5506-16.  PMID 7559336
[ 2 ] Hansen MR, Tranekjaer Jorgensen J, Dandanell G   Xanthosine utilization in Salmonella enterica serovar Typhimurium is recovered by a single aspartate-to-glycine substitution in xanthosine phosphorylase.   J Bacteriol. 2006 Jun;188(11):4153-7.  PMID 16707709

Step NameStep NumRequiredEvidence (Method)Evidence Go Terms
xanthosine phosphorylaseXapAYESTIGR01699 (HMM): xanthosine phosphorylase
xanthosine permeaseXapBYES2219 (RULE_BASE)
xanthosine operon regulatory protein XapRXapRYES2244 (RULE_BASE)
XapX proteinXapXNOTIGR03510 (HMM-CLUST): XapX domain

Parent Properties
GenProp0816nucleoside catabolism/utilization pathways

Sibling Properties
GenProp0461utilization of deoxynucleosides
GenProp0728AMP metabolism using type III Rubisco