The domain within your query sequence starts at position 5 and ends at position 128; the E-value for the NDUF_B4 domain shown below is 5.5e-67.

KYKPAPLATLPSTLDPAEYDVSPETRRAQVERLSIRARLKREYLLQYNDPKRVSHIEDPA
LIRWTYARSANIYPNFRPTPKNSLLGAVAGFGPLIFWYYVFKTDRDRKERLIQEGKLDRK
FNIS

NDUF_B4

NDUF_B4
PFAM accession number:PF07225
Interpro abstract (IPR009866):

This family contains human NADH-ubiquinone oxidoreductase subunit NDUFB4 and related sequences.

NADH:ubiquinone oxidoreductase (complex I) ( EC 1.6.5.3 ) is a respiratory-chain enzyme that catalyses the transfer of two electrons from NADH to ubiquinone in a reaction that is associated with proton translocation across the membrane (NADH + ubiquinone = NAD+ + ubiquinol) [ (PUBMED:1470679) ]. Complex I is a major source of reactive oxygen species (ROS) that are predominantly formed by electron transfer from FMNH(2). Complex I is found in bacteria, cyanobacteria (as a NADH-plastoquinone oxidoreductase), archaea [ (PUBMED:10940377) ], mitochondria, and in the hydrogenosome, a mitochondria-derived organelle. In general, the bacterial complex consists of 14 different subunits, while the mitochondrial complex contains homologues to these subunits in addition to approximately 31 additional proteins [ (PUBMED:18394423) ].

GO component:mitochondrion (GO:0005739)
GO function:NADH dehydrogenase (ubiquinone) activity (GO:0008137)

This is a PFAM domain. For full annotation and more information, please see the PFAM entry NDUF_B4