The domain within your query sequence starts at position 27 and ends at position 388; the E-value for the P2X_receptor domain shown below is 1.5e-149.

WDYETPKVIVVRNRRLGFVHRMVQLLILLYFVWVASGAGTALSHRYVFIVQKSYQDSETG
PESSIITKVKGITMSEHKVWDVEEYVKPPEGGSVVSIITRIEVTPSQTLGTCPESMRVHS
STCHLDDDCVAGQLDMQGNGIRTGRCVPYYHGDSKTCEVSAWCPVEDGTSENHFLGKMAP
NFTILIKNSIHYPKFKFSKGNIASQKSDYLKHCTFDQDSDPYCPIFRLGFIVEQAGENFT
ELAHKGGVIGVIINWNCDLDLSESECNPKYSFRRLDPKYDPASSGYNFRFAKYYKINGTT
TTRTLIKAYGIRIDVIVHGQAGKFSLIPTIINLATALTSIGVGSFLCDWILLTFMNKNKL
YS

P2X_receptor

P2X_receptor
PFAM accession number:PF00864
Interpro abstract (IPR001429):

P2X purinoceptors are cell membrane ion channels, gated by adenosine 5'-triphosphate (ATP) and other nucleotides; they have been found to be widely expressed on mammalian cells, and, by means of their functional properties, can be differentiated into three sub-groups. The first group is almost equally well activated by ATP and its analogue alpha,betamethylene-ATP, whereas, the second group is not activated by the latter compound. A third type of receptor (also called P2Z) is distinguished by the fact that repeated or prolonged agonist application leads to the opening of much larger pores, allowing large molecules to traverse the cell membrane. This increased permeability rapidly leads to cell death, and lysis.

Molecular cloning studies have identified seven P2X receptor subtypes, designated P2X1-P2X7. These receptors are proteins that share 35-48% amino acid identity, and possess two putative transmembrane (TM) domains, separated by a long (~270 residues) intervening sequence, which is thought to form an extracellular loop. Around 1/4 of the residues within the loop are invariant between the cloned subtypes, including 10 characteristic cysteines.

Studies of the functional properties of heterologously expressed P2X receptors, together with the examination of their distribution in native tissues, suggests they likely occur as both homo- and heteromultimers in vivo [(PUBMED:10414359), (PUBMED:12270951)].

This entry represents all P2X purinoreceptor subtypes.

GO process:cation transmembrane transport (GO:0098655), response to ATP (GO:0033198)
GO component:integral component of plasma membrane (GO:0005887)
GO function:extracellularly ATP-gated cation channel activity (GO:0004931), purinergic nucleotide receptor activity (GO:0001614)

This is a PFAM domain. For full annotation and more information, please see the PFAM entry P2X_receptor