UniProt functional annotation for Q59196

UniProt code: Q59196.

Organism:		Bacillus circulans.
Taxonomy:		Bacteria; Firmicutes; Bacilli; Bacillales; Bacillaceae; Bacillus.
Function:		Catalyzes the reversible conversion of 3- phosphohydroxypyruvate to phosphoserine and of 3-hydroxy-2-oxo-4- phosphonooxybutanoate to phosphohydroxythreonine. {ECO:0000269|PubMed:16532449}.
Catalytic activity:		Reaction=2-oxoglutarate + O-phospho-L-serine = 3-phosphooxypyruvate + L-glutamate; Xref=Rhea:RHEA:14329, ChEBI:CHEBI:16810, ChEBI:CHEBI:18110, ChEBI:CHEBI:29985, ChEBI:CHEBI:57524; EC=2.6.1.52; Evidence={ECO:0000269|PubMed:8695645};
Catalytic activity:		Reaction=2-oxoglutarate + 4-(phosphooxy)-L-threonine = (R)-3-hydroxy-2- oxo-4-phosphooxybutanoate + L-glutamate; Xref=Rhea:RHEA:16573, ChEBI:CHEBI:16810, ChEBI:CHEBI:29985, ChEBI:CHEBI:58452, ChEBI:CHEBI:58538; EC=2.6.1.52; Evidence={ECO:0000269|PubMed:8695645};
Cofactor:		Name=pyridoxal 5'-phosphate; Xref=ChEBI:CHEBI:597326; Evidence={ECO:0000269|PubMed:16532449, ECO:0000269|Ref.4}; Note=Binds 1 pyridoxal phosphate per subunit. {ECO:0000269|PubMed:16532449, ECO:0000269|Ref.4};
Biophysicochemical properties:		Kinetic parameters: KM=1 mM for glutamate (at pH 7) {ECO:0000269|PubMed:16532449}; KM=0.2 mM for glutamate (at pH 9) {ECO:0000269|PubMed:16532449}; KM=0.1 mM for phosphohydroxypyruvate (at pH 7) {ECO:0000269|PubMed:16532449}; KM=0.09 mM for phosphohydroxypyruvate (at pH 9) {ECO:0000269|PubMed:16532449}; Vmax=6 nmol/min/mg enzyme for the reaction forming phosphoserine (at pH 7) {ECO:0000269|PubMed:16532449}; Vmax=10 nmol/min/mg enzyme for the reaction forming phosphoserine (at pH 9) {ECO:0000269|PubMed:16532449}; pH dependence: Optimum pH is 9.0. At pH 9.5, retains more 60% of its maximum activity. Inactive below pH 6. {ECO:0000269|PubMed:16532449}; Temperature dependence: Thermal denaturation midpoint (Tm) is 71 degrees Celsius at pH 6 and is lowered around 58 degrees Celsius at pH 8.5 and 10. {ECO:0000269|PubMed:16532449};
Pathway:		Amino-acid biosynthesis; L-serine biosynthesis; L-serine from 3-phospho-D-glycerate: step 2/3.
Pathway:		Cofactor biosynthesis; pyridoxine 5'-phosphate biosynthesis; pyridoxine 5'-phosphate from D-erythrose 4-phosphate: step 3/5.
Subunit:		Homodimer. {ECO:0000269|PubMed:16532449, ECO:0000269|PubMed:8695645, ECO:0000269|Ref.4}.
Subcellular location:		Cytoplasm {ECO:0000250}.
Miscellaneous:		Significant conformational rearrangements are involved in response to pH changes.
Similarity:		Belongs to the class-V pyridoxal-phosphate-dependent aminotransferase family. SerC subfamily. {ECO:0000305}.

Annotations taken from UniProtKB at the EBI.