HPT1/YDR399W Summary Help

Standard Name HPT1 1
Systematic Name YDR399W
Alias BRA6 2
Feature Type ORF, Verified
Description Dimeric hypoxanthine-guanine phosphoribosyltransferase; catalyzes the transfer of the phosphoribosyl portion of 5-phosphoribosyl-alpha-1-pyrophosphate to a purine base (either guanine or hypoxanthine) to form pyrophosphate and a purine nucleotide (either guanosine monophosphate or inosine monophosphate); mutations in the human homolog HPRT1 can cause Lesch-Nyhan syndrome and Kelley-Seegmiller syndrome (3, 4, 5 and see Summary Paragraph)
Also known as: HPRT 5
Name Description Hypoxanthine guanine PhosphoribosylTransferase 6
Gene Product Alias HGPRTase 3
Chromosomal Location
ChrIV:1270068 to 1270733 | ORF Map | GBrowse
Gene Ontology Annotations All HPT1 GO evidence and references
  View Computational GO annotations for HPT1
Molecular Function
Manually curated
Biological Process
Manually curated
Cellular Component
Regulators 7 genes
Classical genetics
Large-scale survey
152 total interaction(s) for 98 unique genes/features.
Physical Interactions
  • Affinity Capture-MS: 3
  • Affinity Capture-RNA: 3
  • Affinity Capture-Western: 1
  • Co-crystal Structure: 1
  • PCA: 1
  • Two-hybrid: 1

Genetic Interactions
  • Dosage Rescue: 1
  • Negative Genetic: 130
  • Phenotypic Suppression: 5
  • Positive Genetic: 6

Expression Summary
Length (a.a.) 221
Molecular Weight (Da) 25,191
Isoelectric Point (pI) 5.48
Phosphorylation PhosphoGRID | PhosphoPep Database
sequence information
ChrIV:1270068 to 1270733 | ORF Map | GBrowse
Last Update Coordinates: 2011-02-03 | Sequence: 1996-07-31
Subfeature details
Most Recent Updates
Coordinates Sequence
CDS 1..666 1270068..1270733 2011-02-03 1996-07-31
Retrieve sequences
Analyze Sequence
S288C only
S288C vs. other species
S288C vs. other strains
External Links All Associated Seq | E.C. | Entrez Gene | Entrez RefSeq Protein | MIPS | Search all NCBI (Entrez) | UniProtKB
Primary SGDIDS000002807

HPT1 encodes hypoxanthine-guanine phosphoribosyltransferase, an enzyme involved in the salvage pathway of purine nucleotide biosynthesis (1). Hpt1p catalyzes the conversion of the purine bases hypoxanthine and guanine to the nucleotides IMP and GMP (4). The enzyme functions as a dimer and can be inhibited in vitro by its end-product GMP (5, 6). In hpt1 null mutants, if the de novo pathway of guanine nucleotide biosynthesis is blocked, either through mutation of ade2 or by the addition of mycophenolic acid, cells are unable to grow even with the addition of guanine to the media (1, 2). Null mutants are also resistant to the hypoxanthine/guanine analog 8-azaguanine as well as to the anti-cancer drug cisplatin (1, 7). In humans, partial and complete deficiencies of the HPT1 ortholog HPRT1 (OMIM) are associated with the genetic disorders HPRT-related gout/Kelley-Seegmiller syndrome (OMIM) and Lesch-Nyhan syndrome (OMIM), respectively (2 and references therein).

Last updated: 2006-09-18 Contact SGD

References cited on this page View Complete Literature Guide for HPT1
1) Woods RA, et al.  (1983) Hypoxanthine: guanine phosphoribosyltransferase mutants in Saccharomyces cerevisiae. Mol Gen Genet 191(3):407-12
2) Guetsova ML, et al.  (1997) The isolation and characterization of Saccharomyces cerevisiae mutants that constitutively express purine biosynthetic genes. Genetics 147(2):383-97
3) Ali LZ and Sloan DL  (1986) Activation of hypoxanthine/guanine phosphoribosyltransferase from yeast by divalent zinc and nickel ions. J Inorg Biochem 28(4):407-15
4) Ali LZ and Sloan DL  (1982) Studies of the kinetic mechanism of hypoxanthine-guanine phosphoribosyltransferase from yeast. J Biol Chem 257(3):1149-55
5) Nussbaum RL and Caskey CT  (1981) Purification and characterization of hypoxanthine-guanine phosphoribosyltransferase from Saccharomyces cerevisiae. Biochemistry 20(16):4584-90
6) Lecoq K, et al.  (2000) Yeast GMP kinase mutants constitutively express AMP biosynthesis genes by phenocopying a hypoxanthine-guanine phosphoribosyltransferase defect. Genetics 156(3):953-61
7) Huang RY, et al.  (2005) Genome-wide screen identifies genes whose inactivation confer resistance to cisplatin in Saccharomyces cerevisiae. Cancer Res 65(13):5890-7