Q58185 (MPTA_METJA) Reviewed, UniProtKB/Swiss-Prot

Names and origin

Protein names

Recommended name:
GTP cyclohydrolase MptA
EC=3.5.4.n2

Gene names

Name:	mptA
Ordered Locus Names:	MJ0775

Organism

Methanocaldococcus jannaschii (strain ATCC 43067 / DSM 2661 / JAL-1 / JCM 10045 / NBRC 100440) (Methanococcus jannaschii) [Reference proteome] [HAMAP]

Taxonomic identifier

243232 [NCBI]

Taxonomic lineage

cellular organisms › Archaea › Euryarchaeota › Methanococci › Methanococcales › Methanocaldococcaceae › Methanocaldococcus › Methanocaldococcus jannaschii

Protein attributes

Sequence length	313 AA.
Sequence status	Complete.
Protein existence	Evidence at protein level

General annotation (Comments)

Function	Converts GTP to 7,8-dihydro-D-neopterin 2',3'-cyclic phosphate, the first intermediate in the biosynthesis of coenzyme methanopterin. It is also able to utilize a variety of GTP analogs as substrates, including GDP, beta,gamma-methylene-GTP and GTP-[gamma-thio]. Ref.2
Catalytic activity	GTP + H2O = formate + 7,8-dihydro-D-neopterin 2',3'-cyclic phosphate + diphosphate. Ref.2
Cofactor	Binds 1 Fe2+ ion per subunit. Manganese and zinc can be used to a lesser extent, but not at a relevant physiological concentration. Ref.2
Enzyme regulation	Inhibited by GTP concentrations greater than 0.3 mM and by 2-amino-5-formylamino-6-ribofuranosylamino-4(3H)-pyrimidinone 5'-phosphate (fapyGMP). Partial inhibition is observed when 2 mM GMP, dGTP, or 7-methyl-GTP was included along with 2 mM GTP. Ref.2
Pathway	Cofactor biosynthesis; 5,6,7,8-tetrahydromethanopterin biosynthesis. HAMAP-Rule MF_01527_A
Subunit structure	Homodimer. Ref.2
Miscellaneous	MptA is the archetype of a new class of GTP cyclohydrolases that catalyzes a series of reactions most similar to that seen with GTPCHI but unique in that the cyclic phosphate is the product. HAMAP-Rule MF_01527_A
Sequence similarities	Belongs to the GTP cyclohydrolase IV family.
Biophysicochemical properties	Kinetic parameters: Other purine nucleotides including ATP, ITP, dGTP, GMP, and 7-methyl-GTP do not serve as substrates. Vmax=13 nmol/min/mg enzyme with GDP as substrate (at pH 7.2) Ref.2 Vmax=30 nmol/min/mg enzyme with GTP as substrate (at pH 7.2) Vmax=39 nmol/min/mg enzyme with GTP-[gamma-thio] as substrate (at pH 7.2) Vmax=3 nmol/min/mg enzyme with beta,gamma-methylene-GTP as substrate (at pH 7.2) pH dependence: Optimum pH is 6.5. Temperature dependence: MptA loses 27% activity when it incubates for 10 min at 80 degrees Celsius, 60% activity at 90 degrees Celsius, and 89% activity at 100 degrees Celsius.
Sequence caution	The sequence AAB98765.1 differs from that shown. Reason: Erroneous initiation.

Ontologies

Keywords
Ligand	Iron Manganese Metal-binding Zinc
Molecular function	Hydrolase
Technical term	Complete proteome Reference proteome
Gene Ontology (GO)
Molecular_function	GTP cyclohydrolase activity Inferred from electronic annotation. Source: HAMAP iron ion binding Inferred from electronic annotation. Source: HAMAP
Complete GO annotation...

Sequence annotation (Features)

	Feature key	Position(s)	Length	Description	Graphical view	Feature identifier
Molecule processing
	Chain	1 – 313	313	GTP cyclohydrolase MptA HAMAP-Rule MF_01527_A		PRO_0000147743
Sites
	Site	160	1	May be catalytically important
Experimental info
	Mutagenesis	47	1	E → D: Unchanged. Ref.2
	Mutagenesis	98	1	H → N: Unchanged. Ref.2
	Mutagenesis	197	1	H → N: Strong decrease in specific activity. Ref.2
	Mutagenesis	290	1	H → N: Strong decrease in specific activity. Ref.2
	Mutagenesis	292	1	H → N: Strong decrease in specific activity. Ref.2

Sequences

	Sequence		Length	Mass (Da)
	Q58185 [UniParc]. Last modified May 5, 2009. Version 2. Checksum: 4CCA67352C1773CF	FASTA	313	35,873
	10 20 30 40 50 60 MNWRCDVQNF EPDVKISLTR VGVTNLKKLV RLKRTNKRPI ILLSTFEVFV NLPSSQKGIH 70 80 90 100 110 120 MSRNPEVIEG IIDEALELES YEMETICEEI VKRLFEKHEY ATEAEVFMVS DFMTKEKSPI 130 140 150 160 170 180 SGKYSQEIHK IMGGAKGIKK DDEIELTKIV GAEVVGITAC PCAQNLIKEI CIKNLKEKGF 190 200 210 220 230 240 SDEDIDKILD SVIFATHNQR GIGRIILEVP TGYDIEIMDI IEIIKKSMSA EIHGILKRAD 250 260 270 280 290 300 EAYVVEQSHK NPKFVEDCVR EMAKRVVEKF KHLPDETKVL IRQINMESIH RHDAFAEKVA 310 TLGELRRELL SYE

References

	« Hide 'large scale' referencesShow 'large scale' references »
[1]	"Complete genome sequence of the methanogenic archaeon, Methanococcus jannaschii." Bult C.J., White O., Olsen G.J., Zhou L., Fleischmann R.D., Sutton G.G., Blake J.A., FitzGerald L.M., Clayton R.A., Gocayne J.D., Kerlavage A.R., Dougherty B.A., Tomb J.-F., Adams M.D., Reich C.I., Overbeek R., Kirkness E.F., Weinstock K.G. , Merrick J.M., Glodek A., Scott J.L., Geoghagen N.S.M., Weidman J.F., Fuhrmann J.L., Nguyen D., Utterback T.R., Kelley J.M., Peterson J.D., Sadow P.W., Hanna M.C., Cotton M.D., Roberts K.M., Hurst M.A., Kaine B.P., Borodovsky M., Klenk H.-P., Fraser C.M., Smith H.O., Woese C.R., Venter J.C. Science 273:1058-1073(1996) [PubMed] [Europe PMC] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA]. Strain: ATCC 43067 / DSM 2661 / JAL-1 / JCM 10045 / NBRC 100440.
[2]	"Characterization of an Fe(2+)-dependent archaeal-specific GTP cyclohydrolase, MptA, from Methanocaldococcus jannaschii." Grochowski L.L., Xu H., Leung K., White R.H. Biochemistry 46:6658-6667(2007) [PubMed] [Europe PMC] [Abstract] Cited for: FUNCTION, CATALYTIC ACTIVITY, SUBUNIT, COFACTOR, SUBSTRATE SPECIFICITY, ENZYME REGULATION, REACTION MECHANISM, MUTAGENESIS OF GLU-47; HIS-98; HIS-197; HIS-290 AND HIS-292, BIOPHYSICOCHEMICAL PROPERTIES.

Cross-references

Sequence databases
EMBL GenBank DDBJ	L77117 Genomic DNA. Translation: AAB98765.1. Different initiation.
PIR	G64396.
RefSeq	NP_247760.1. NC_000909.1.
3D structure databases
ModBase	Search...
Protein-protein interaction databases
STRING	243232.MJ0775.
Protocols and materials databases
DNASU	1451652.
StructuralBiologyKnowledgebase	Search...
Genome annotation databases
EnsemblBacteria	AAB98765; AAB98765; MJ_0775.
GeneID	1451652.
KEGG	mja:MJ_0775.
Phylogenomic databases
eggNOG	COG1469.
KO	K09007.
OMA	VEDCVRE.
ProtClustDB	PRK13675.
Enzyme and pathway databases
BioCyc	MetaCyc:MONOMER-14599.
UniPathway	UPA00065.
Family and domain databases
Gene3D	3.10.270.10. 1 hit.
HAMAP	MF_01527_A. GTP_cyclohydrol_A.
InterPro	IPR003801. GTP_cyclohydrolase_FolE2/MptA. IPR022840. GTP_cyclohydrolase_MptA. IPR002042. Uricase. [Graphical view]
Pfam	PF02649. GCHY-1. 1 hit. [Graphical view]
TIGRFAMs	TIGR00294. TIGR00294. 1 hit.
ProtoNet	Search...

Entry information

Entry name

MPTA_METJA

Accession

Primary (citable) accession number: Q58185

Entry history

Integrated into UniProtKB/Swiss-Prot:	November 1, 1997
Last sequence update:	May 5, 2009
Last modified:	May 1, 2013
This is version 72 of the entry and version 2 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation program

Prokaryotic Protein Annotation Program