Domon-like ligand-binding domains; DOMON-like domains can be found in all three kindgoms of life and are a diverse group of ligand binding domains that have been shown to interact with sugars and hemes. DOMON domains were initially thought to confer protein-protein interactions. They were subsequently found as a heme-binding motif in cellobiose dehydrogenase, an extracellular fungal oxidoreductase that degrades both lignin and cellulose, and in ethylbenzene dehydrogenase, an enzyme that aids in the anaerobic degradation of hydrocarbons. The domain interacts with sugars in the type 9 carbohydrate binding modules (CBM9), which are present in a variety of glycosyl hydrolases, and it can also be found at the N-terminus of sensor histidine kinases.

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                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958780802  94 KIKVEDCGRTKGCFRYGKpGC-NAETCDYFLSYRMIGADVEFELSADT--DGWVAVGFSSDKKMAPSLVM 160
Cdd:cd09628     1 PISYSGCGKTKGCFGLPV-GCdPSKDCNFLVTYRVDGDSVEFELSGKTvdDGYVAVGFSDDKKMGDDDVV 69

DOMON domain of stromal cell-derived receptor 2 (ferric chelate reductase 1) and related proteins; Stromal cell-derived receptor 2 (or ferric chelate reductase 1) reduces Fe(3+) to Fe(2+) ahead of iron transport from the endosome to the cytoplasm. This transmembrane protein is a member of the cytochrome b561 family and contains a DOMON domain which may bind to heme or another ligand. DOMON-like domains can be found in all three kindgoms of life and are a diverse group of ligand binding domains that have been shown to interact with sugars and hemes. DOMON domains were initially thought to confer protein-protein interactions. They were subsequently found as a heme-binding motif in cellobiose dehydrogenase, an extracellular fungal oxidoreductase that degrades both lignin and cellulose, and in ethylbenzene dehydrogenase, an enzyme that aids in the anaerobic degradation of hydrocarbons. The domain interacts with sugars in the type 9 carbohydrate binding modules (CBM9), which are present in a variety of glycosyl hydrolases, and it can also be found at the N-terminus of sensor histidine kinases.

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                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958780802  94 KIKVEDCGRTKGCFRYGKpGC-NAETCDYFLSYRMIGADVEFELSADT--DGWVAVGFSSDKKMAPSLVM 160
Cdd:cd09628     1 PISYSGCGKTKGCFGLPV-GCdPSKDCNFLVTYRVDGDSVEFELSGKTvdDGYVAVGFSDDKKMGDDDVV 69

DOMON domain; The DOMON (named after dopamine beta-monooxygenase N-terminal) domain is 110-125 residues long. It is predicted to form an all beta fold with up to 11 strands and is secreted to the extracellular compartment. The beta-strand folding produces a hydrophobic pocket which appears to bind soluble haem. This is consistent with the predominant architectures where the protein is associated with cytochromes or enzymatic domains whose activity involves redox or electron transfer reactions potentially as a direct participant in the electron transfer process. The DOMON domain superfamily, of which this is just one member, shows (1) multiple hydrophobic residues that contribute to the hydrophobic core of the strands of the beta-sandwich, and small residues found at the boundaries of strands and loops, (2) a strongly conserved charged residue (usually arginine/lysine) at the end of strand 9, which possibly stabilizes the loop between 9 and 10, and (3) a polar residue (usually histidine, lysine or arginine), that interacts or coordinates with ligands. The suggested superfamily includes both haem- and sugar-binding members: the haem-binding families being the ethyl-Benzoate dehydrogenase family EB_dh, pfam09459, the cellobiose dehydrogenase family CBDH and this family, and the sugar-binding families being the xylanases, CBM_4_9, pfam02018. The common feature of the superfamily is the 11-beta-strand structure, although the first and eleventh strands are not well conserved either within families or between families.

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                  ....*....|....*....|....*....|....*....|...
gi 1958780802 121 YFLSYRMIGAD--VEFELSA-DTDGWVAVGFSSDKKMAPSLVM 160
Cdd:pfam03351   1 YTVSWKVDGDNdeIEFELSGkNTNGWVAIGFSDDGKMGNADVV 43

DOMON domain of stromal cell-derived receptor 2 (ferric chelate reductase 1) and related proteins; Stromal cell-derived receptor 2 (or ferric chelate reductase 1) reduces Fe(3+) to Fe(2+) ahead of iron transport from the endosome to the cytoplasm. This transmembrane protein is a member of the cytochrome b561 family and contains a DOMON domain which may bind to heme or another ligand. DOMON-like domains can be found in all three kindgoms of life and are a diverse group of ligand binding domains that have been shown to interact with sugars and hemes. DOMON domains were initially thought to confer protein-protein interactions. They were subsequently found as a heme-binding motif in cellobiose dehydrogenase, an extracellular fungal oxidoreductase that degrades both lignin and cellulose, and in ethylbenzene dehydrogenase, an enzyme that aids in the anaerobic degradation of hydrocarbons. The domain interacts with sugars in the type 9 carbohydrate binding modules (CBM9), which are present in a variety of glycosyl hydrolases, and it can also be found at the N-terminus of sensor histidine kinases.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958780802  94 KIKVEDCGRTKGCFRYGKpGC-NAETCDYFLSYRMIGADVEFELSADT--DGWVAVGFSSDKKMAPSLVM 160
Cdd:cd09628     1 PISYSGCGKTKGCFGLPV-GCdPSKDCNFLVTYRVDGDSVEFELSGKTvdDGYVAVGFSDDKKMGDDDVV 69

DOMON-like domain of copper-dependent monooxygenases and related proteins; This diverse family characterizes DOMON domains found in dopamine beta-hydroxylase (DBH), monooxygenase X (MOX), and various other proteins, some of which contain DOMON domains exclusively; the family is not restricted to eukaryotes. DBH is a membrane-bound enzyme that converts dopamine to L-norepinephrine, and plays a central role in the metabolism of catecholamine neurotransmitters. DOMON domains were initially thought to confer protein-protein interactions. They were subsequently found as a heme-binding motif in cellobiose dehydrogenase, an extracellular fungal oxidoreductase that degrades both lignin and cellulose, and in ethylbenzene dehydrogenase, an enzyme that aids in the anaerobic degradation of hydrocarbons. The domain interacts with sugars in the type 9 carbohydrate binding modules (CBM9), which are present in a variety of glycosyl hydrolases, and it can also be found at the N-terminus of sensor histidine kinases.

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                  ....*....|....*....|....*....|....*....|
gi 1958780802 119 CDYFLSYRMIGAD-VEFELSADTDGWVAVGFSSDKKMAPS 157
Cdd:cd09631     7 GNFSLSWSVDGEGtITFELSARTTGWVGIGFSPDGGMVGA 46