Q9AQI0 (HMGA_PSEOC) Reviewed, UniProtKB/Swiss-Prot

Names and origin

Protein names

Recommended name:
4-hydroxy-4-methyl-2-oxoglutarate aldolase

Alternative name(s):
4-hydroxy-2-oxoglutarate aldolase
EC=4.1.1.3
EC=4.1.3.-
EC=4.1.3.16
EC=4.1.3.17

Gene names

Name:

proA

Organism

Pseudomonas ochraceae (Pseudomonas straminea)

Taxonomic identifier

47882 [NCBI]

Taxonomic lineage

cellular organisms › Bacteria › Proteobacteria › Gammaproteobacteria › Pseudomonadales › Pseudomonadaceae › Pseudomonas › Pseudomonas aeruginosa group

Protein attributes

Sequence length	227 AA.
Sequence status	Complete.
Protein existence	Evidence at protein level

General annotation (Comments)

Function	Plays a role in protocatechuate degradation. Has a broad substrate specificity and catalyzes the aldol cleavage of 4-hydroxy-4-methyl-2-oxoglutarate, 4-hydroxy-2-oxoglutarate and 4-carboxy-4-hydroxy-2-oxoadipate, and the decarboxylation of oxaloacetate. Preferentially cleaves the L-isomer of 4-carboxy-4-hydroxy-2-oxoadipate, and has lower activity towards 4-hydroxy-4-methyl-2-oxoglutarate and 4-Hydroxy-2-oxoglutarate. Does not cleave 4-hydroxy-2-oxovalerate, citrate, 4-hydroxy-2-oxobutyrate, 2-oxoglutarate or fructose-1,6-bisphosphate. Ref.1 Ref.2
Catalytic activity	4-hydroxy-4-methyl-2-oxoglutarate = 2 pyruvate. Ref.1 Ref.2 2-hydroxy-4-oxobutane-1,2,4-tricarboxylate = oxaloacetate + pyruvate. Ref.1 Ref.2 4-hydroxy-2-oxoglutarate = pyruvate + glyoxylate. Ref.1 Ref.2 Oxaloacetate = pyruvate + CO2. Ref.1 Ref.2
Cofactor	Divalent metal cations. Probably Mg2+. Ref.1 Ref.2
Enzyme regulation	Cleavage of 4-carboxy-4-hydroxy-2-oxoadipate, and to a lesser extent 4-hydroxy-4-methyl-2-oxoglutarate, is inhibited by lysine modification caused by diethyl pyrocarbonate. Decarboxylation of oxaloacetate is unaffected by diethyl pyrocarbonate. Inhibited by BeCl2, CaCl2, NiCl2, BaCl2, HgCl2, SrSO4, CrCl3 and FeCl3. Partially inhibited by p-chloromercuribenzoate and N-ethylmaleimide. Activated by inorganic phosphate, arsenate, phosphorous acid, acetyl phosphate, thiamine diphosphate, ADP, ATP and diphosphate. Ref.2 Ref.3 Ref.4
Subunit structure	Homohexamer. Ref.2
Induction	By growth on aromatic carboxylates such as phthalate, terephthalate, m-hydroxybenzoate and p-hydroxybenzoate. Ref.2 Ref.3 Ref.4
Sequence similarities	Belongs to the LigK/PcmE family.
Biophysicochemical properties	Kinetic parameters: KM=0.044 mM for DL-4-carboxy-4-hydroxy-2-oxoadipate Ref.1 Ref.2 Ref.3 KM=0.019 mM for L-4-carboxy-4-hydroxy-2-oxoadipate Ref.1 KM=0.15 mM for D-4-carboxy-4-hydroxy-2-oxoadipate Ref.1 KM=1.25 mM for DL-4-hydroxy-4-methyl-2-oxoglutarate Ref.1 KM=0.24 mM for DL-4-hydroxy-2-oxoglutarate Ref.1 KM=0.50 mM for oxaloacetate Ref.1 Vmax=1250 µmol/min/mg enzyme with DL-4-carboxy-4-hydroxy-2-oxoadipate as substrate Ref.1 Vmax=1220 µmol/min/mg enzyme with L-4-carboxy-4-hydroxy-2-oxoadipate as substrate Vmax=67.6 µmol/min/mg enzyme with D-4-carboxy-4-hydroxy-2-oxoadipate as substrate Vmax=213 µmol/min/mg enzyme with DL-4-hydroxy-4-methyl-2-oxoglutarate as substrate Ref.1 Vmax=1.3 µmol/min/mg enzyme with DL-4-hydroxy-2-oxoglutarate as substrate Ref.1 Vmax=20.8 µmol/min/mg enzyme with oxaloacetate as substrate pH dependence: Optimum pH varies depending on the substrate used and phosphate concentration. In the absence of inorganic phosphate pH optima are 6.6 for L-4-carboxy-4-hydroxy-2-oxoadipate, 8.0 for D-4-carboxy-4-hydroxy-2-oxoadipate, 6.7 and 8.0 for DL-4-carboxy-4-hydroxy-2-oxoadipate, 8.3 for DL-4-hydroxy-4-methyl-2-oxoglutarate, 9.3 for DL-4-hydroxy-2-oxoglutarate and 8.8 for oxaloacetate. In the presence of 3 mM inorganic phosphate pH optima are more alkaline: 8.2 for L-4-carboxy-4-hydroxy-2-oxoadipate, 8.6 for D-4-carboxy-4-hydroxy-2-oxoadipate, 8.2 for DL-4-carboxy-4-hydroxy-2-oxoadipate, 8.9 for DL-4-hydroxy-4-methyl-2-oxoglutarate, 9.4 for DL-4-hydroxy-2-oxoglutarate and 8.9 for oxaloacetate. Stable at pH 6.0 to pH 9.5. Ref.3 Temperature dependence: Retains 50% of maximum activity after incubation at 54 degrees Celsius for 10 minutes. Ref.2

Ontologies

Keywords
Ligand	Magnesium Metal-binding
Molecular function	Lyase
Technical term	Direct protein sequencing
Gene Ontology (GO)
Biological_process	protocatechuate catabolic process Inferred from direct assay Ref.1. Source: UniProtKB
Molecular_function	4-hydroxy-2-oxoglutarate aldolase activity Inferred from direct assay Ref.1. Source: UniProtKB 4-hydroxy-4-methyl-2-oxoglutarate aldolase activity Inferred from direct assay Ref.1. Source: UniProtKB metal ion binding Inferred from electronic annotation. Source: UniProtKB-KW oxaloacetate decarboxylase activity Inferred from direct assay Ref.1. Source: UniProtKB
Complete GO annotation...

Sequence annotation (Features)

	Feature key	Position(s)	Length	Description	Graphical view	Feature identifier
Molecule processing
	Chain	1 – 227	227	4-hydroxy-4-methyl-2-oxoglutarate aldolase		PRO_0000403973
Regions
	Region	99 – 100	2	Substrate By similarity
Sites
	Metal binding	120	1	Magnesium By similarity
	Binding site	119	1	Substrate By similarity

Sequences

	Sequence		Length	Mass (Da)
	Q9AQI0 [UniParc]. Last modified June 1, 2001. Version 1. Checksum: F56501D5BDD0262F	FASTA	227	24,068
	10 20 30 40 50 60 MYELGVVYRN IQRADRAAAD GLAALGSATV HEAMGRVGLL KPYMRPIYAG KQVSGTAVTV 70 80 90 100 110 120 LLQPGDNWMM HVAAEQIQPG DIVVAAVTAE CTDGYFGDLL ATSFQARGAR ALIIDAGVRD 130 140 150 160 170 180 VKTLQEMDFP VWSKAISSKG TIKATLGSVN IPIVCAGMLV TPGDVIVADD DGVVCVPAAR 190 200 210 220 AVEVLAAAQK RESFEGEKRA KLASGVLGLD MYKMREPLEK AGLKYID

References

[1]	"Cloning, sequencing, and expression of the gene encoding 4-hydroxy-4-methyl-2-oxoglutarate aldolase from Pseudomonas ochraceae NGJ1." Maruyama K., Miwa M., Tsujii N., Nagai T., Tomita N., Harada T., Sobajima H., Sugisaki H. Biosci. Biotechnol. Biochem. 65:2701-2709(2001) [PubMed] [Europe PMC] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA], PROTEIN SEQUENCE OF 1-22, FUNCTION, CATALYTIC ACTIVITY, COFACTOR, BIOPHYSICOCHEMICAL PROPERTIES. Strain: NGJ1.
[2]	"Purification and properties of 4-hydroxy-4-methyl-2-oxoglutarate aldolase from Pseudomonas ochraceae grown on phthalate." Maruyama K. J. Biochem. 108:327-333(1990) [PubMed] [Europe PMC] [Abstract] Cited for: FUNCTION, CATALYTIC ACTIVITY, COFACTOR, ENZYME REGULATION, BIOPHYSICOCHEMICAL PROPERTIES, SUBUNIT, INDUCTION.
[3]	"Activation of Pseudomonas ochraceae 4-hydroxy-4-methyl-2-oxoglutarate aldolase by inorganic phosphate." Maruyama K. J. Biochem. 108:334-340(1990) [PubMed] [Europe PMC] [Abstract] Cited for: ENZYME REGULATION, BIOPHYSICOCHEMICAL PROPERTIES.
[4]	"Chemical modification of Pseudomonas ochraceae 4-hydroxy-4-methyl-2-oxoglutarate aldolase by diethyl pyrocarbonate." Maruyama K. J. Biochem. 110:976-981(1991) [PubMed] [Europe PMC] [Abstract] Cited for: ENZYME REGULATION.

Cross-references

Sequence databases
EMBL GenBank DDBJ	AB050935 Genomic DNA. Translation: BAB21456.3.
3D structure databases
ProteinModelPortal	Q9AQI0.
ModBase	Search...
Protocols and materials databases
StructuralBiologyKnowledgebase	Search...
Enzyme and pathway databases
BioCyc	MetaCyc:MONOMER-3244.
Family and domain databases
Gene3D	3.50.30.40. 1 hit.
InterPro	IPR014165. LigK_PcmE. IPR005493. RNase_E_inh/diMeMenaQ_MeTrfase. [Graphical view]
Pfam	PF03737. Methyltransf_6. 1 hit. [Graphical view]
SUPFAM	SSF89562. RNaseE_inh/diMeMenaQ_MeTrfase. 1 hit.
TIGRFAMs	TIGR02798. ligK_PcmE. 1 hit.
ProtoNet	Search...

Entry information

Entry name

HMGA_PSEOC

Accession

Primary (citable) accession number: Q9AQI0

Entry history

Integrated into UniProtKB/Swiss-Prot:	February 8, 2011
Last sequence update:	June 1, 2001
Last modified:	April 3, 2013
This is version 35 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation program

Prokaryotic Protein Annotation Program