Protein
NADH-quinone oxidoreductase subunit 4
Organism
Thermus thermophilus (strain HB8 / ATCC 27634 / DSM 579)
Function
NDH-1 shuttles electrons from NADH, via FMN and iron-sulfur (Fe-S) centers, to quinones in the respiratory chain. The immediate electron acceptor for the enzyme in this species is menaquinone. Couples the redox reaction to proton translocation (for every two electrons transferred, four hydrogen ions are translocated across the cytoplasmic membrane), and thus conserves the redox energy in a proton gradient required for the synthesis of ATP. The Nqo4 subunit may contain the quinone-binding site.
Similarity
Belongs to the complex I 49 kDa subunit family.
Sequence
MREEFLEEIPLDAPPEEAKELRTEVMTLNVGPQHPSTHGVLRLMVTLSGEEVLEVVPHIGYLHTGFEKTMEHRTYLQNITYTPRMDYLHSFAHDLAYALAVEKLLGAVVPPRAETIRVILNELSRLASHLVFLGTGLLDLGALTPFFYAFRERETILDLFEWVTGQRFHHNYIRIGGVKEDLPEEFVPELKKLLEVLPHRIDEYEALFAESPIFYERARGVGVIPPEVAIDLGLTGGSLRASGVNYDVRKAYPYSGYETYTFDVPLGERGDVFDRMLVRIREMRESVKIIKQALERLEPGPVRDPNPQITPPPRHLLETSMEAVIYHFKHYTEGFHPPKGEVYVPTESARGELGYYIVSDGGSMPYRVKVRAPSFVNLQSLPYACKGEQVPDMVAIIASLDPVMGDVDR