Reviewed, UniProtKB/Swiss-Prot Q44238 (PEPQ_ALTSX)

Names and origin

Protein names

Recommended name:
    Xaa-Pro dipeptidase
      Short name=X-Pro dipeptidase
    EC=3.4.13.9
Alternative name(s):
    Proline dipeptidase
      Short name=Prolidase
    Imidodipeptidase
    Organophosphorus acid anhydrolase 2
      Short name=OPAA-2
    EC=3.1.8.2
    DFPase
    Phosphotriesterase
    EC=3.1.8.1
    Paraoxon hydrolase

Gene names

Name:	pepQ
Synonyms:	opaA

Organism

Alteromonas sp.

Taxonomic identifier

232 [NCBI]

Taxonomic lineage

Bacteria › Proteobacteria › Gammaproteobacteria › Alteromonadales › Alteromonadaceae › Alteromonas

Protein attributes

Sequence length	517 AA.
Sequence status	Complete.
Sequence processing	The displayed sequence is not processed.
Protein existence	Evidence at protein level.

General annotation (Comments)

Function	Splits dipeptides with a prolyl or hydroxyprolyl residue in the C-terminal position and a nonpolar amino acid at the N-terminal position. Also catalyzes the hydrolysis of toxic organophosphorus cholinesterase-inhibiting compounds including insecticide paraoxon and nerve gases such as diisopropylfluorophosphate (DFP), O-isopropyl methylphosphonofluoridate (sarin), O-pinacolyl methylphosphonofluoridate (soman), and O-cyclohexyl methylphosphonofluoridate. Ref.1 Ref.2 Ref.3 Ref.4
Catalytic activity	Hydrolysis of Xaa-|-Pro dipeptides; also acts on aminoacyl-hydroxyproline analogs. No action on Pro-|-Pro. HAMAP MF_01279 Diisopropyl fluorophosphate + H2O = diisopropyl phosphate + fluoride. HAMAP MF_01279 An aryl dialkyl phosphate + H2O = dialkyl phosphate + an aryl alcohol. HAMAP MF_01279
Cofactor	Binds 2 manganese ions per monomer. Ref.1
Subunit structure	Monomer. Ref.2
Biotechnological use	Can be used for the catalytic detoxification of some nerve agents neurotoxins. HAMAP MF_01279
Miscellaneous	Has a stereoselective preference for isomers with R-configuration at the phosphorous center of sarin and soman, and with S-configuration in phosphotriesters. HAMAP MF_01279
Sequence similarities	Belongs to the peptidase M24B family. Bacterial-type prolidase subfamily.
Biophysicochemical properties	Kinetic parameters: KM=2.99 mM for diisopropylfluorophosphate HAMAP MF_01279 KM=1.57 mM for O-isopropyl methylphosphonofluoridate KM=2.48 mM for O-pinacolyl methylphosphonofluoridate KM=0.63 mM for O-cyclohexyl methylphosphonofluoridate KM=1.27 mM for a chromogenic soman analog Vmax=230 µmol/min/mg enzyme with diisopropylfluorophosphate as substrate Vmax=442 µmol/min/mg enzyme with O-isopropyl methylphosphonofluoridate as substrate Vmax=151 µmol/min/mg enzyme with O-pinacolyl methylphosphonofluoridate as substrate Vmax=652 µmol/min/mg enzyme with O-cyclohexyl methylphosphonofluoridate as substrate Vmax=52 µmol/min/mg enzyme with a chromogenic soman analog as substrate pH dependence: Optimum pH is 8.5 with DFP as substrate. Temperature dependence: Optimum temperature is 50 degrees Celsius.

Ontologies

Keywords
Biological process	Detoxification
Ligand	Manganese Metal-binding
Molecular function	Dipeptidase Hydrolase Metalloprotease Protease
Gene Ontology (GO)
Biological process	cellular process Inferred from electronic annotation. Source: InterPro proteolysis Inferred from electronic annotation. Source: InterPro response to toxin Inferred from electronic annotation. Source: UniProtKB-KW
Molecular function	aryldialkylphosphatase activity Inferred from electronic annotation. Source: EC diisopropyl-fluorophosphatase activity Inferred from electronic annotation. Source: EC dipeptidase activity Inferred from electronic annotation. Source: HAMAP manganese ion binding Inferred from electronic annotation. Source: UniProtKB-KW metalloexopeptidase activity 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 – 517	517	Xaa-Pro dipeptidase HAMAP MF_01279		PRO_0000298944
Sites
	Metal binding	244	1	Manganese 2 By similarity
	Metal binding	255	1	Manganese 1 By similarity
	Metal binding	255	1	Manganese 2 By similarity
	Metal binding	336	1	Manganese 1 By similarity
	Metal binding	381	1	Manganese 1 By similarity
	Metal binding	420	1	Manganese 1 By similarity
	Metal binding	420	1	Manganese 2 By similarity

Sequences

	Sequence		Length	Mass (Da)
	Q44238-1 [UniParc]. Last modified January 15, 2008. Version 3. Checksum: 9B92D811445C72A3	FASTA	517	58,998
	10 20 30 40 50 60 MNKLAVLYAE HIATLQKRTR EIIERENLDG VVFHSGQAKR QFLDDMYYPF KVNPQFKAWL 70 80 90 100 110 120 PVIDNPHCWI VANGTDKPKL IFYRPVDFWH KVPDEPNEYW ADYFDIELLV KPDQVEKLLP 130 140 150 160 170 180 YDKARFAYIG EYLEVAQALG FELMNPEPVM NFYHYHRAYK TQYELACMRE ANKIAVQGHK 190 200 210 220 230 240 AARDAFFQGK SEFEIQQAYL LATQHSENDN AYGNIVALNE NCAILHYTHF DRVAPATHRS 250 260 270 280 290 300 FLIDAGANFN GYAADITRTY DFTGEGEFAE LVATMKQHQI ALCNQLAPGK LYGELHLDCH 310 320 330 340 350 360 QRVAQTLSDF NIVDLSADEI VAKGITSTFF PHGLGHHIGL QVHDVGGFMA DEQGAHQEPP 370 380 390 400 410 420 EGHPFLRCTR KIEANQVFTI EPGLYFIDSL LGDLAATDNN QHINWDKVAE LKPFGGIRIE 430 440 450 460 470 480 DNIIVHEDSL ENMTRELRAR LTTHSLRGLS APQFSINDPA VMSEYSYPSE PLSYEEEIKK 490 500 510 STFIVHVRTR RILVRRRTLS PILIAVTPMP AITAGLM

References

[1]	"Cloning and expression of a gene encoding a bacterial enzyme for decontamination of organophosphorus nerve agents and nucleotide sequence of the enzyme." Cheng T.-C., Harvey S.P., Chen G.L. Appl. Environ. Microbiol. 62:1636-1641(1996) [PubMed: 8633861] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA], FUNCTION, COFACTOR, BIOPHYSICOCHEMICAL PROPERTIES. Strain: JD6.5.
[2]	"Purification and properties of an organophosphorus acid anhydrase from a halophilic bacterial isolate." DeFrank J.J., Cheng T.-C. J. Bacteriol. 173:1938-1943(1991) [PubMed: 2001997] [Abstract] Cited for: FUNCTION, SUBUNIT, BIOPHYSICOCHEMICAL PROPERTIES. Strain: JD6.5.
[3]	"Nucleotide sequence of a gene encoding an organophosphorus nerve agent degrading enzyme from Alteromonas haloplanktis." Cheng T.-C., Liu L., Wang B., Wu J., DeFrank J.J., Anderson D.M., Rastogi V.K., Hamilton A.B. J. Ind. Microbiol. Biotechnol. 18:49-55(1997) [PubMed: 9079288] [Abstract] Cited for: FUNCTION. Strain: JD6.5.
[4]	"Substrate and stereochemical specificity of the organophosphorus acid anhydrolase from Alteromonas sp. JD6.5 toward p-nitrophenyl phosphotriesters." Hill C.M., Wu F., Cheng T.-C., DeFrank J.J., Raushel F.M. Bioorg. Med. Chem. Lett. 10:1285-1288(2000) [PubMed: 10866401] [Abstract] Cited for: FUNCTION, SUBSTRATE SPECIFICITY, STEREOSELECTIVITY. Strain: JD6.5.
[5]	"Stereochemical specificity of organophosphorus acid anhydrolase toward p-nitrophenyl analogs of soman and sarin." Hill C.M., Li W.-S., Cheng T.-C., DeFrank J.J., Raushel F.M. Bioorg. Chem. 29:27-35(2001) [PubMed: 11300693] [Abstract] Cited for: STEREOSELECTIVITY.

Cross-references

Sequence databases
EMBLGenBankDDBJ	U29240 Genomic DNA. Translation: AAB05590.1.
3D structure databases
HSSP	HSSP built from PDB template 1A16 based on UniProtKB P15034.
ModBase	Search...
Protein family/group databases
MEROPS	M24.003.
Enzyme and pathway databases
BioCyc	MetaCyc:MON-7712.
Family and domain databases
HAMAP	MF_01279. [Tree]
InterPro	IPR000994. Pept_M24_structural-domain. IPR001131. Peptidase_M24B_aminopep-P_CS. [Graphical view]
Gene3D	G3DSA:3.90.230.10. Peptidase_M24_cat_core. 1 hit.
PANTHER	PTHR10804. Peptidase_M24_cat_core. 1 hit.
Pfam	PF00557. Peptidase_M24. 1 hit. [Graphical view]
PROSITE	PS00491. PROLINE_PEPTIDASE. 1 hit. [Graphical view]
ProtoNet	Search...

Entry information

Entry name

PEPQ_ALTSX

Accession

Primary (citable) accession number: Q44238

Entry history

Integrated into UniProtKB/Swiss-Prot:	August 21, 2007
Last sequence update:	January 15, 2008
Last modified:	June 16, 2009
This is version 45 of the entry and version 3 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation project

HAMAP (High-quality Automated and Manual Annotation of microbial Proteomes)