EC Number   |
General Information  |
Reference |
|---|
   1.9.6.1 | metabolism |
NasST regulates the nitrate-mediated response of nosZ and napE genes, from the dissimilatory denitrification pathway, regulation of nos and nap genes by the NasST system in the absence of nitrate in mutant strains, overview |
-, 742380 |
| 1.9.6.1 | more |
modeling of regulation of nap and nos genes by NasST system in Bradyrhizobium japonicum strain USDA110 and nasS and Nos++ mutant strains |
-, 742380 |
| 1.9.6.1 | more |
NapD is a small cytoplasmic protein that is essential for the activity of the periplasmic nitrate reductase and binds tightly to the twinarginine signal peptide of NapA. NapA is structured in its unbound form. The NapA signal peptide undergoes conformational rearrangement upon interaction with NapD. NapA is at least partially folded when bound by its NapD partner. The NapD chaperone binds primarily at the NapA signal peptide in this system and points towards a role for NapD in the insertion of the molybdenum cofactor |
742486 |
| 1.9.6.1 | more |
the enzyme shows a sulfur-shift mechanism catalytic mechanism, the active site is deeply buried and centered on the Mo atom, which is hexacoordinated to four sulfur atoms of two pyranopterin guanosine dinucleotides, one inorganic sulfur, and one S (Nap) atom from the side chain of a Cys, structure, structure overview. Above the region of the metal center, the enzyme presents an arginine residue, Arg354,that is proposed to be key for stabilization and substrate binding. The side chain of this residues probably interacts electrostatically with the substrates, compensating for the negative charge and favoring their interaction with the negatively charged active site |
741478 |
| 1.9.6.1 | more |
the enzyme shows a sulfur-shift mechanism catalytic mechanism, the active site is deeply buried and centered on the Mo atom, which is hexacoordinated to four sulfur atoms of two pyranopterin guanosine dinucleotides, one inorganic sulfur, and one S (Nap) atom from the side chain of a Cys, structure. Above the region of the metal center, the enzyme presents an arginine residue, Arg354,that is proposed to be key for stabilization and substrate binding. The side chain of this residues probably interacts electrostatically with the substrates, compensating for the negative charge and favoring their interaction with the negatively charged active site. Comparisons of reaction mechanisms of members of the DMSO reductase family and structure analysis and modelling, overview. The NapA, product of the napA gene, is the catalytic subunit that contains the Mo-bisPGD and one 4Fe-4S center involved in electron transfer. Similar to other periplasmic Mo- and W-enzymes, immature NapA contains a signal peptide that is recognized by the TAT (twin arginine translocator) system. Prior to translocation, the two metallic cofactors are incorporated into NapA with the aid of the chaperone NapD, which accompanies the assembled metalloenzyme to the transporter, maturation mechanism of Mo. NapB contains two c-type hemes and is assembled and secreted into the periplasm by the Ccm (cytochrome c maturation) machinery independently from NapA. Once in the periplasm they form the heterodimer NapAB, except in the case of monomeric Naps. It is remarkable that napM is present only when the napB gene is absent. NapM is a tetrahemic c-type cytochrome. This cytochrome may mediate electron transfer to NapA in a similar way that NapB does in heterodimeric Naps. NapC is a membrane-anchored protein harboring four c-type hemes belonging to the NapC/NirT family. In bacteria like Desulfovibrio desulfuricans ATCC 27774 and Escherichia coli K12, where nitrate reduction catalyzed by Nap is coupled to an energy conserving process, the genes napG and napH are always present |
742319 |
| 1.9.6.1 | more |
the enzyme shows a sulfur-shift mechanism catalytic mechanism, the active site is deeply buried and centered on the Mo atom, which is hexacoordinated to four sulfur atoms of two pyranopterin guanosine dinucleotides, one inorganic sulfur, and one S (Nap) atom from the side chain of a Cys, structure. Above the region of the metal center, the enzyme presents an arginine residue, that is proposed to be key for stabilization and substrate binding. The side chain of this residues probably interacts electrostatically with the substrates, compensating for the negative charge and favoring their interaction with the negatively charged active site. Comparisons of reaction mechanisms of members of the DMSO reductase family and structure analysis and modelling, overview. The NapA (product of the napA gene) is the catalytic subunit that contains the Mo-bis-PGD and one 4Fe-4S center involved in electron transfer. Similar to other periplasmic Mo- and W-enzymes, immature NapA contains a signal peptide that is recognized by the TAT (twin arginine translocator) system. Prior to translocation, the two metallic cofactors are incorporated into NapA with the aid of the chaperone NapD, which accompanies the assembled metalloenzyme to the transporter, maturation mechanism of Mo. NapB contains two c-type hemes and is assembled and secreted into the periplasm by the Ccm (cytochrome c maturation) machinery independently from NapA. Once in the periplasm they form the heterodimer NapAB, except in the case of monomeric Naps. It is remarkable that napM is present only when the napB gene is absent. NapM is a tetrahemic c-type cytochrome. This cytochrome may mediate electron transfer to NapA in a similar way that NapB does in heterodimeric Naps. NapC is a membrane-anchored protein harboring four c-type hemes belonging to the NapC/NirT family. In some bacteria, where nitrate reduction catalyzed by Nap is coupled to an energy conserving process, the genes napG and napH are always present. Nap from Paracoccus pantotrophus catalyzes nitrate reduction to consume the excess of reducing equivalents generated by consumption of the carbon source, which is in agreement with the lack of napG and napH genes |
-, 742319 |
| 1.9.6.1 | more |
the enzyme shows a sulfur-shift mechanism catalytic mechanism, the active site is deeply buried and centered on the Mo atom, which is hexacoordinated to four sulfur atoms of two pyranopterin guanosine dinucleotides, one inorganic sulfur, and one S (Nap) atom from the side chain of a Cys, structure. Above the region of the metal center, the enzyme presents an arginine residue, that is proposed to be key for stabilization and substrate binding. The side chain of this residues probably interacts electrostatically with the substrates, compensating for the negative charge and favoring their interaction with the negatively charged active site. Comparisons of reaction mechanisms of members of the DMSO reductase family and structure analysis and modelling, overview. The NapA (product of the napA gene) is the catalytic subunit that contains the Mo-bisPGD and one 4Fe-4S center involved in electron transfer. Similar to other periplasmic Mo- and W-enzymes, immature NapA contains a signal peptide that is recognized by the TAT (Twin Arginine Translocator) system. Prior to translocation, the two metallic cofactors are incorporated into NapA with the aid of the chaperone NapD, which accompanies the assembled metalloenzyme to the transporter, maturation mechanism of Mo. NapB contains two c-type hemes and is assembled and secreted into the periplasm by the Ccm (cytochrome c maturation) machinery independently from NapA. Once in the periplasm they form the heterodimer NapAB, except in the case of monomeric Naps. It is remarkable that napM is present only when the napB gene is absent. NapM is a tetrahemic c-type cytochrome. This cytochrome may mediate electron transfer to NapA in a similar way that NapB does in heterodimeric Naps. NapC is a membrane-anchored protein harboring four c-type hemes belonging to the NapC/NirT family. In some bacteria, where nitrate reduction catalyzed by Nap is coupled to an energy conserving process, the genes napG and napH are always present. But the Nap from Pseudomonas sp. G-179 lacks these two genes |
-, 742319 |
| 1.9.6.1 | more |
the Salmonella enterica serovar Typhimurium genome contains three nitrate reductases, encoded by the narGHI, narZYV, and napABC genes |
-, 742645 |
| 1.9.6.1 | physiological function |
a mutant strain defective for napA is not able to denitrify and grow on nitrate. The wild-type strain reaches 40 000 ppm of N2O emission and its growth is 10fold higher than that of the mutant strain. In the presence of nitrite as terminal electron acceptor, both wild-type and mutant are able to denitrify and to grow with no significant difference between both strains. NapA plays a role in Agrobacterium fabrum C58 fitness but is not involved in A. fabrum C58 root colonization |
-, 764679 |
| 1.9.6.1 | physiological function |
Escherichia coli is a Gram-negative bacterium that can use nitrate during anaerobic respiration. The catalytic subunit of the involved periplasmic nitrate reductase NapA contains two types of redox cofactor and is exported across the cytoplasmic membrane by the twin-arginine protein transport pathway |
742486 |
