The domain within your query sequence starts at position 7 and ends at position 288; the E-value for the Na_K-ATPase domain shown below is 5.7e-108.

KKSCSQRMAEFRHYCWNPDTGQMLGRTPARWVWISLYYAGFYVVMTGLFALCIYVLMQTI
DPYTPDYQDQLKSPGVTLRPDVYGERGLKISYNVSENSSWAGLTHTLHSFLAGYTPASQQ
DSINCTSEKYFFQESFAAPNHTKFSCKFTADMLQNCSGLADPSFGFEEGKPCFIIKMNRI
VKFLPSNNTAPRVDCTFQDDPQKPRKDTEPLQVEYYPPNGTFSLHYFPYYGKKAQPHYSN
PLVAAKLLNVPKNMQVSIVCKILADHVTFNNPHDPYEGKVEF

Na_K-ATPase

Na_K-ATPase
PFAM accession number:PF00287
Interpro abstract (IPR000402): This entry represents the sodium/potassium-transporting ATPase subunit beta. This is the non-catalytic component of the active enzyme, which catalyses the hydrolysis of ATP coupled with the exchange of Na+ and K+ ions across the plasma membrane. The beta subunit regulates, through assembly of alpha/beta heterodimers, the number of sodium pumps transported to the plasma membrane [(PUBMED:9648860)].
GO process:potassium ion transport (GO:0006813), sodium ion transport (GO:0006814)
GO component:sodium:potassium-exchanging ATPase complex (GO:0005890)

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