LIPID MAPS® Gene/Proteome Database (LMPD)

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LMPD Record

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LMP011427

UniProt Annotations

Entry Information
Gene NameUDP-sugar pyrophosphorylase
Protein EntryUSP_ARATH
UniProt IDQ9C5I1
SpeciesArabidopsis
Comments
Comment typeDescription
Biophysicochemical PropertiesKinetic parameters: KM=0.13 mM for glucuronic acid-1-phosphate {ECO:0000269|PubMed:16757173}; KM=0.42 mM for glucose-1-phosphate {ECO:0000269|PubMed:16757173}; KM=0.16 mM for UTP {ECO:0000269|PubMed:16757173}; KM=0.56 mM for UDP-glucuronic acid {ECO:0000269|PubMed:16757173}; KM=0.72 mM for UPD-glucose {ECO:0000269|PubMed:16757173}; KM=0.15 mM for pyrophosphate {ECO:0000269|PubMed:16757173}; Vmax=3.47 nmol/min/mg enzyme for the forward reaction with glucuronic acid-1-phosphate as substrate {ECO:0000269|PubMed:16757173}; Vmax=5.76 nmol/min/mg enzyme for the forward reaction with glucose-1-phosphate as substrate {ECO:0000269|PubMed:16757173}; Vmax=4.24 nmol/min/mg enzyme for the reverse reaction with UDP- glucuronic acid as substrate {ECO:0000269|PubMed:16757173}; Vmax=4.95 nmol/min/mg enzyme for the reverse reaction with UDP- glucose as substrate {ECO:0000269|PubMed:16757173}; Note=High activity with glucose-1-phosphate > glucuronic acid-1- phosphate > galactose-1-phosphate, but low or no activity with N-acetylglucosamine-1-phosphate, fucose-1-phosphate, mannose-1- phosphate, inositol-1-phosphate or glucose-6-phosphate.; pH dependence: Optimum pH is 7.5-8.5. Inactive at or below pH 5.0. {ECO:0000269|PubMed:16757173}; Temperature dependence: Optimum temperature is 45 degrees Celsius. {ECO:0000269|PubMed:16757173};
Catalytic ActivityUTP + a monosaccharide 1-phosphate = diphosphate + UDP-monosaccharide.
CofactorName=Mg(2+); Xref=ChEBI:CHEBI:18420; Name=Mn(2+); Xref=ChEBI:CHEBI:29035;
Developmental StageExpressed during pollen development, peaking at the tricellular stage. {ECO:0000269|PubMed:16757173}.
Disruption PhenotypePlants produce collapsed, nonviable pollen grains. {ECO:0000269|PubMed:16557401}.
FunctionRequired for the synthesis of the intine, the pectocellulosic inner wall of developing pollen. May function as the terminal enzyme of the myo-inositol oxidation (MIO) pathway. May also play a role in the salvage pathway for synthesis of nucleotide sugars. {ECO:0000269|PubMed:16557401, ECO:0000269|PubMed:16757173}.
Sequence CautionSequence=BAA98074.1; Type=Erroneous gene model prediction; Evidence={ECO:0000305};
SimilarityBelongs to the USP family. {ECO:0000305}.
Tissue SpecificityUbiquitous, but most abundant in rosette leaves, inflorescences, stems, stamens and pollen. {ECO:0000269|PubMed:16757173}.