UniProt functional annotation for P11926



	UniProt functional annotation for P11926

UniProt code: P11926.

Organism: Homo sapiens (Human).

Taxonomy: Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia; Eutheria; Euarchontoglires; Primates; Haplorrhini; Catarrhini; Hominidae; Homo.

Function: Catalyzes the first and rate-limiting step of polyamine biosynthesis that converts ornithine into putrescine, which is the precursor for the polyamines, spermidine and spermine. Polyamines are essential for cell proliferation and are implicated in cellular processes, ranging from DNA replication to apoptosis. {ECO:0000269|PubMed:17900240}.

Catalytic activity: Reaction=H(+) + L-ornithine = CO2 + putrescine; Xref=Rhea:RHEA:22964, ChEBI:CHEBI:15378, ChEBI:CHEBI:16526, ChEBI:CHEBI:46911, ChEBI:CHEBI:326268; EC=4.1.1.17; Evidence={ECO:0000269|PubMed:17407445};

Cofactor: Name=pyridoxal 5'-phosphate; Xref=ChEBI:CHEBI:597326; Evidence={ECO:0000269|PubMed:17407445, ECO:0000269|PubMed:26443277};

Activity regulation: Inhibited by S-nitrosylation (PubMed:10462479, PubMed:11461922). Inhibited by antizymes (AZs) OAZ1, OAZ2 and OAZ3 in response to polyamine levels. AZs inhibit the assembly of the functional homodimer by binding to ODC monomers. Additionally, OAZ1 targets ODC monomers for ubiquitin-independent proteolytic destruction by the 26S proteasome (PubMed:17900240). Inhibited by 1-amino-oxy-3- aminopropane (APA, an isosteric analog of putrescine) (PubMed:17407445). Irreversibly inhibited by alpha- difluoromethylornithine (DFMO) (PubMed:17407445). {ECO:0000269|PubMed:10462479, ECO:0000269|PubMed:11461922, ECO:0000269|PubMed:17407445, ECO:0000269|PubMed:17900240}.

Biophysicochemical properties: Kinetic parameters: KM=0.08 mM for L-ornithine {ECO:0000269|PubMed:17407445}; Note=kcat is 3.3 sec(-1) with L-ornithine as substrate. {ECO:0000269|PubMed:17407445};

Pathway: Amine and polyamine biosynthesis; putrescine biosynthesis via L-ornithine pathway; putrescine from L-ornithine: step 1/1.

Subunit: Homodimer. Only the dimer is catalytically active, as the active sites are constructed of residues from both monomers (Probable). Does not form a heterodimer with AZIN2 (By similarity). {ECO:0000250|UniProtKB:P00860, ECO:0000305|PubMed:10623504}.

Induction: Down-regulated in response to enterovirus 71 (EV71) infection (at protein level). {ECO:0000269|PubMed:16548883}.

Ptm: S-Nitrosylation inhibits the enzyme. S-Nitrosylated in vitro on 4 cysteine residues. {ECO:0000269|PubMed:10462479, ECO:0000269|PubMed:11461922}.

Similarity: Belongs to the Orn/Lys/Arg decarboxylase class-II family. {ECO:0000305}.

Annotations taken from UniProtKB at the EBI.


Organism:		Homo sapiens (Human).
Taxonomy:		Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia; Eutheria; Euarchontoglires; Primates; Haplorrhini; Catarrhini; Hominidae; Homo.



Function:		Catalyzes the first and rate-limiting step of polyamine biosynthesis that converts ornithine into putrescine, which is the precursor for the polyamines, spermidine and spermine. Polyamines are essential for cell proliferation and are implicated in cellular processes, ranging from DNA replication to apoptosis. {ECO:0000269\|PubMed:17900240}.


Catalytic activity:		Reaction=H(+) + L-ornithine = CO2 + putrescine; Xref=Rhea:RHEA:22964, ChEBI:CHEBI:15378, ChEBI:CHEBI:16526, ChEBI:CHEBI:46911, ChEBI:CHEBI:326268; EC=4.1.1.17; Evidence={ECO:0000269\|PubMed:17407445};
Cofactor:		Name=pyridoxal 5'-phosphate; Xref=ChEBI:CHEBI:597326; Evidence={ECO:0000269\|PubMed:17407445, ECO:0000269\|PubMed:26443277};
Activity regulation:		Inhibited by S-nitrosylation (PubMed:10462479, PubMed:11461922). Inhibited by antizymes (AZs) OAZ1, OAZ2 and OAZ3 in response to polyamine levels. AZs inhibit the assembly of the functional homodimer by binding to ODC monomers. Additionally, OAZ1 targets ODC monomers for ubiquitin-independent proteolytic destruction by the 26S proteasome (PubMed:17900240). Inhibited by 1-amino-oxy-3- aminopropane (APA, an isosteric analog of putrescine) (PubMed:17407445). Irreversibly inhibited by alpha- difluoromethylornithine (DFMO) (PubMed:17407445). {ECO:0000269\|PubMed:10462479, ECO:0000269\|PubMed:11461922, ECO:0000269\|PubMed:17407445, ECO:0000269\|PubMed:17900240}.
Biophysicochemical properties:		Kinetic parameters: KM=0.08 mM for L-ornithine {ECO:0000269\|PubMed:17407445}; Note=kcat is 3.3 sec(-1) with L-ornithine as substrate. {ECO:0000269\|PubMed:17407445};
Pathway:		Amine and polyamine biosynthesis; putrescine biosynthesis via L-ornithine pathway; putrescine from L-ornithine: step 1/1.
Subunit:		Homodimer. Only the dimer is catalytically active, as the active sites are constructed of residues from both monomers (Probable). Does not form a heterodimer with AZIN2 (By similarity). {ECO:0000250\|UniProtKB:P00860, ECO:0000305\|PubMed:10623504}.
Induction:		Down-regulated in response to enterovirus 71 (EV71) infection (at protein level). {ECO:0000269\|PubMed:16548883}.
Ptm:		S-Nitrosylation inhibits the enzyme. S-Nitrosylated in vitro on 4 cysteine residues. {ECO:0000269\|PubMed:10462479, ECO:0000269\|PubMed:11461922}.
Similarity:		Belongs to the Orn/Lys/Arg decarboxylase class-II family. {ECO:0000305}.