Reviewed, UniProtKB/Swiss-Prot Q09068 (UREI_HELPY)

Names and origin

Protein names

Recommended name:
    Acid-activated urea channel
Alternative name(s):
    Urease accessory protein ureI

Gene names

Name:	ureI
Ordered Locus Names:	HP_0071

Organism

Helicobacter pylori (Campylobacter pylori) [Complete proteome] [HAMAP]

Taxonomic identifier

210 [NCBI]

Taxonomic lineage

Bacteria › Proteobacteria › Epsilonproteobacteria › Campylobacterales › Helicobacteraceae › Helicobacter

Protein attributes

Sequence length	195 AA.
Sequence status	Complete.
Sequence processing	The displayed sequence is not processed.
Protein existence	Evidence at protein level.

General annotation (Comments)

Function	Functions as a specific, H(+)-activated urea channel that increases the rate of urea entry into the cytoplasm, resulting in activation of cytoplasmic urease at acidic medium pH. Is essential for H.pylori gastric survival and colonization. Is necessary for the adaptation of urease activity to the extracellular pH, as in the presence of urea, ureI rapidly enhances the production of ammonia in the extracellular medium when the pH of the medium was decreased to pH5 or below.
Subunit structure	Forms a membrane complex with the urease ureA/ureB.
Subcellular location	Cell inner membrane; Multi-pass membrane protein.
Miscellaneous	UreI-mediated transport is urea-specific, passive, non-saturable, non-electrogenic, and temperature independent.
Sequence similarities	Belongs to the amiS/ureI family.
Caution	Was originally (Ref.1) thought to be an accessory protein required for nickel incorporation at the urease active site or for nickel transport. Actually, has been shown (Ref.5) not to be required for the assembly of a catalytically active urease. In Ref.7, mutational analysis indicated that His-123, His-131, and His-193 were important for acid activation of urea uptake in the Xenopus oocytes model, but in H.pylori itself (Ref.8) His-193 seems to be the only histidine that is crucial for ureI activation at low pH.

Ontologies

Keywords
Biological process	Transport
Cellular component	Cell inner membrane Cell membrane Membrane
Domain	Transmembrane
Technical term	Complete proteome
Gene Ontology (GO)
Cellular component	plasma membrane Inferred from electronic annotation. Source: UniProtKB-SubCell
Complete GO annotation...

Sequence annotation (Features)

	Feature key	Position(s)	Length	Description	Graphical view
Molecule processing
	Chain	1 – 195	195	Acid-activated urea channel
Regions
	Topological domain	1	1	Periplasmic Probable
	Transmembrane	2 – 21	20	Potential
	Topological domain	22 – 33	12	Cytoplasmic Probable
	Transmembrane	34 – 53	20	Potential
	Topological domain	54 – 74	21	Periplasmic Probable
	Transmembrane	75 – 93	19	Potential
	Topological domain	94 – 103	10	Cytoplasmic Probable
	Transmembrane	104 – 122	19	Potential
	Topological domain	123 – 140	18	Periplasmic Probable
	Transmembrane	141 – 158	18	Potential
	Topological domain	159 – 171	13	Cytoplasmic Probable
	Transmembrane	172 – 191	20	Potential
	Topological domain	192 – 195	4	Periplasmic Probable
Natural variations
	Natural variant	42	1	I → V in strain: LSU1037-1, LSU1037-5, LSU1062-1, LSU1062-3, LSU2003-1 and LSU2003-7.
	Natural variant	45	1	I → V in strain: 85P, HPK5, LSU1037-1, LSU1037-5, LSU1062-1, LSU1062-3, LSU2003-1 and LSU2003-7.
	Natural variant	47	1	V → A in strain: LSU2003-1 and LSU2003-7.
	Natural variant	51	1	S → F in strain: LSU2003-1 and LSU2003-7.
	Natural variant	53	1	L → V in strain: LSU2003-7.
	Natural variant	54	1	H → N in strain: 85P, HPK5 and NQ1712.
	Natural variant	66	1	A → V in strain: LSU1037-1, LSU1037-5, LSU1062-1, LSU1062-3, LSU2003-1, LSU2003-7 and NQ1712.
	Natural variant	74	1	S → N in strain: 85P and HPK5.
	Natural variant	77	1	G → E in strain: HPK5.
	Natural variant	94	1	N → S in strain: HPK5.
	Natural variant	98	1	G → N in strain: HPK5.
	Natural variant	116	1	I → V in strain: LSU1037-1, LSU1037-5, LSU1062-1, LSU1062-3, LSU2003-1 and LSU2003-7.
	Natural variant	171	1	P → L in strain: LSU1037-1.
Experimental info
	Mutagenesis	71	1	H → G: No loss of acid activation of urea uptake
	Mutagenesis	123	1	H → R or G: No loss of acid activation of urea uptake; when expressed in H.pylori itself. Opposite result; when expressed in the Xenopus oocytes model
	Mutagenesis	131	1	H → G: No loss of acid activation of urea uptake
	Mutagenesis	193	1	H → G: Loss of acid activation of urea uptake

Sequences

	Sequence		Length	Mass (Da)
	Q09068-1 [UniParc]. Last modified November 1, 1997. Version 2. Checksum: 6A8F3E621CB2B37C	FASTA	195	21,706
	10 20 30 40 50 60 MLGLVLLYVG IVLISNGICG LTKVDPKSTA VMNFFVGGLS IICNIVVITY SALHPTAPVE 70 80 90 100 110 120 GAEDIAQVSH HLTSFYGPAT GLLFGFTYLY AAINHTFGLD WRPYSWYSLF VAINTIPAAI 130 140 150 160 170 180 LSHYSDMLDD HKVLGITEGD WWAIIWLAWG VLWLTAFIEN ILKIPLGKFT PWLAIIEGIL 190 TAWIPAWLLF IQHWV

References

	« Hide 'large scale' referencesShow 'large scale' references »
[1]	"Expression of Helicobacter pylori urease genes in Escherichia coli grown under nitrogen-limiting conditions." Cussac V., Ferrero R.L., Labigne A. J. Bacteriol. 174:2466-2473(1992) [PubMed: 1313413] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA]. Strain: 85P.
[2]	"Identification of the urease operon in Helicobacter pylori and its control by mRNA decay in response to pH." Akada J.K., Shirai M., Takeuchi H., Tsuda M., Nakazawa T. Mol. Microbiol. 36:1071-1084(2000) [PubMed: 10844692] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA]. Strain: HPK5.
[3]	"Recombination and mutation during long-term gastric colonization by Helicobacter pylori: estimates of clock rates, recombination size and minimal age." Falush D., Kraft C., Taylor N.S., Correa P., Fox J.G., Achtman M., Suerbaum S. Proc. Natl. Acad. Sci. U.S.A. 98:15056-15061(2001) [PubMed: 11742075] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA]. Strain: LSU1037-1, LSU1037-5, LSU1062-1, LSU1062-3, LSU2003-1, LSU2003-7 and NQ1712.
[4]	"The complete genome sequence of the gastric pathogen Helicobacter pylori." Tomb J.-F., White O., Kerlavage A.R., Clayton R.A., Sutton G.G., Fleischmann R.D., Ketchum K.A., Klenk H.-P., Gill S.R., Dougherty B.A., Nelson K.E., Quackenbush J., Zhou L., Kirkness E.F., Peterson S.N., Loftus B.J., Richardson D.L., Dodson R.J. , Khalak H.G., Glodek A., McKenney K., FitzGerald L.M., Lee N., Adams M.D., Hickey E.K., Berg D.E., Gocayne J.D., Utterback T.R., Peterson J.D., Kelley J.M., Cotton M.D., Weidman J.F., Fujii C., Bowman C., Watthey L., Wallin E., Hayes W.S., Borodovsky M., Karp P.D., Smith H.O., Fraser C.M., Venter J.C. Nature 388:539-547(1997) [PubMed: 9252185] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA]. Strain: ATCC 700392 / 26695.
[5]	"The Helicobacter pylori UreI protein is not involved in urease activity but is essential for bacterial survival in vivo." Skouloubris S., Thiberge J.-M., Labigne A., De Reuse H. Infect. Immun. 66:4517-4521(1998) [PubMed: 9712811] [Abstract] Cited for: FUNCTION.
[6]	"A H+-gated urea channel: the link between Helicobacter pylori urease and gastric colonization." Weeks D.L., Eskandari S., Scott D.R., Sachs G. Science 287:482-485(2000) [PubMed: 10642549] [Abstract] Cited for: CHARACTERIZATION, TOPOLOGY, MUTAGENESIS OF HIS-123.
[7]	"Sites of pH regulation of the urea channel of Helicobacter pylori." Weeks D.L., Sachs G. Mol. Microbiol. 40:1249-1259(2001) [PubMed: 11442825] [Abstract] Cited for: FUNCTION, MUTAGENESIS.
[8]	"The Helicobacter pylori UreI protein: role in adaptation to acidity and identification of residues essential for its activity and for acid activation." Bury-Mone S., Skouloubris S., Labigne A., De Reuse H. Mol. Microbiol. 42:1021-1034(2001) [PubMed: 11737644] [Abstract] Cited for: FUNCTION, MUTAGENESIS OF HIS-71; HIS-123; HIS-131 AND HIS-193.
[9]	"Interactions among the seven Helicobacter pylori proteins encoded by the urease gene cluster." Voland P., Weeks D.L., Marcus E.A., Prinz C., Sachs G., Scott D. Am. J. Physiol. 284:G96-G106(2003) [PubMed: 12388207] [Abstract] Cited for: INTERACTION WITH UREASE.

Cross-references

Sequence databases
EMBLGenBankDDBJ	M84338 Genomic DNA. Translation: AAA25022.1. AB032429 Genomic DNA. Translation: BAA84534.1. AJ418323 Genomic DNA. Translation: CAD11209.1. AJ418324 Genomic DNA. Translation: CAD11212.1. AJ418325 Genomic DNA. Translation: CAD11215.1. AJ418326 Genomic DNA. Translation: CAD11218.1. AJ418327 Genomic DNA. Translation: CAD11221.1. AJ418328 Genomic DNA. Translation: CAD11224.1. AJ418331 Genomic DNA. Translation: CAD11233.1. AE000511 Genomic DNA. Translation: AAD07134.1.
PIR	A41834. G64528.
RefSeq	NP_206871.1.
3D structure databases
ModBase	Search...
Protein-protein interaction databases
DIP	DIP:3136N.
Genome annotation databases
GeneID	899995.
GenomeReviews	Gene locus HP_0071 in contig AE000511_GR.
KEGG	hpy:HP0071.
TIGR	HP_0071.
Phylogenomic databases
HOGENOM	Q09068.
Family and domain databases
InterPro	IPR003211. AmiSUreI_transpt. [Graphical view]
Pfam	PF02293. AmiS_UreI. 1 hit. [Graphical view]
ProDom	PD016614. AmiSUreI_transpt. 1 hit. [Graphical view] [Entries sharing at least one domain]
BLOCKS	Search...
Other Resources
ProtoNet	Search...

Entry information

Entry name

UREI_HELPY

Accession

Primary (citable) accession number: Q09068
Secondary accession number(s): Q8VN83 , Q8VN86, Q8VN88, Q8VN89, Q9S0Q4

Entry history

Integrated into UniProtKB/Swiss-Prot:	February 1, 1995
Last sequence update:	November 1, 1997
Last modified:	July 22, 2008
This is version 57 of the entry and version 2 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation project

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