Description

IPR001834 is a NADH:cytochrome b5 reductase-like.

<p>Flavoprotein pyridine nucleotide cytochrome reductases [[cite:PUB00002674]] (FPNCR) catalyse the interchange of reducing equivalents between one-electron carriers and the two-electron-carrying nicotinamide dinucleotides. The enzymes include <ul> <li>ferredoxin:NADP⁺reductases (FNR) [[cite:PUB00002370]].</li> <li>plant and fungal NAD(P)H:nitrate reductases [[cite:PUB00002674], [cite:PUB00005356]].</li> <li>NADH:cytochrome b5 reductases [[cite:PUB00002329]].</li> <li>NADPH:P450 reductases.</li> <li>NADPH:sulphite reductases.</li> <li>nitric oxide synthases.</li> <li>phthalate dioxygenase reductase.</li> <li>and various other flavoproteins.</li> </ul> <p>NADH:cytochrome b5 reductase (CBR) serves as electron donor for cytochrome b5, a ubiquitous electron carrier (see [interpro:IPR001199]), thus participating in a variety of metabolic pathways (including steroid biosynthesis, desaturation and elongation of fatty acids, P450-dependent reactions, methaemoglobin reduction, etc.). A membrane-bound form of CBR is located on the cytosolic side of the endoplasmic reticulum, while a soluble form is found in erythrocytes [[cite:PUB00002329]]. In the membrane-bound form, the N-terminal residue is myristoylated [[cite:PUB00002397]]. Deficiency of the erythrocyte form causes hereditary methaemoglobinemia [[cite:PUB00004935]].</p> <p>In biological nitrate assimilation, reduction of nitrate to nitrite is catalysed by the multidomain redox enzyme NAD(P)H:nitrate reductase (NR). Three forms of NR are known: an NADH-specific enzyme found in higher plants and algae ([ec:1.7.1.1]); an NAD(P)H-bispecific enzyme found in higher plants, algae and fungi ([ec:1.7.1.2]); and an NADPH-specific enzyme found only in fungi ([ec:1.7.1.3]) [[cite:PUB00005356]]. NR can be divided into 3 structure/function domains: the molybdopterin cofactor binds in the N-terminal domain; the central region is the cytochrome b domain, which is similar to animal cytochrome b5 (see [interpro:IPR001199]); and the C-terminal portion of the protein is occupied by the FAD/NAD(P)H binding domain, which is similar to CBR [[cite:PUB00005356]]. The catalytic reduction of nitrate to nitrite can be viewed as a single polypeptide electron transport chain with electron flow from NAD(P)H ->FAD ->cytochrome b5 ->molybdopterin ->NO(3). Thus, the flavin domain of NR is functionally identical to CBR.</p> <p>To date, the 3D-structures of the flavoprotein domain of Zea mays (Maize) nitrate reductase [[cite:PUB00005247]] and of Sus scrofa (Pig) NADH:cytochrome b5 reductase [[cite:PUB00000415]] have been solved. The overall fold is similar to that of ferredoxin:NADP⁺reductase [[cite:PUB00002370]]: the FAD-binding domain (N-terminal) has the topology of an anti-parallel β-barrel, while the NAD(P)-binding domain (C-terminal) has the topology of a classical pyridine dinucleotide-binding fold (i.e. a central parallel β-sheet flanked by 2 helices on each side).</p>

This description is obtained from EB-eye REST.

Associated GO terms

GO predictions are based solely on the InterPro-to-GO mappings published by EMBL-EBI, which are in turn based on the mapping of predicted domains to the InterPro dataset. The InterPro-to-GO mapping was last updated on April 27, 2020, while the GO metadata was last updated on April 27, 2020.

Associated Lotus transcripts 10

Co-occuring domains 1

A list of co-occurring predicted domains within the L. japonicus gene space: