1.9.6.1	evolution	genotyping of different strains from M and G populations, overview. The only mutated gene shared between the strains from populations M and G is bll4572, this gene is mutated in all six strains	-, 742380	
1.9.6.1	evolution	periplasmic nitrate reductase (Nap) from Desulfovibrio desulfuricans and formate dehydrogenase (Fdh) from Escherichia coli K-12, both belonging to the DMSO reductase family, subfamily I, have a very similar structure, but very different activities. The show key differences that tune them for completely different functions in living cells. Both enzymes share almost identical three-dimensional protein foldings and active sites, in terms of coordination number, geometry and nature of the ligands. The substrates of both enzymes (nitrate and formate) are polyatomic anions that also share similar charge and stereochemistry. In terms of the catalytic mechanism, both enzymes have a common activation mechanism (the sulfur-shift mechanism) that ensures a constant coordination number around the metal ion during the catalytic cycle. In spite of these similarities, they catalyze very different reactions: Nap abstracts an oxygen atom from nitrate releasing nitrite, whereas FdH catalyzes a hydrogen atom transfer from formate and releases carbon dioxide. Detailed comparison, overview. A key difference between the catalytic mechanisms of Nap and FdH is the fact that only Mo is used to reduce nitrate but in Fdhs both Mo and W are catalytically competent to oxidize formate to carbon dioxide	741478	
1.9.6.1	evolution	the enzyme belongs to the DMSO reductase family	-, 741958	
1.9.6.1	evolution	the periplasmic nitrate reductase (Nap) from Desulfovibrio desulfuricans belongs to the DMSO reductase family, subfamily I. Classification of Mo-pyranopterin dependent enzymes from the DMSO reductase family, e.g. periplasmic nitrate reductase and formate dehydrogenase, overview. Comparison of the sulfur-shift mechanism in nitrate reductase (Nap) and in formate dehydrogenase (Fdh), detailed overview	742648	
1.9.6.1	evolution	the prokaryotic nitrate reductases can be subgrouped as respiratory nitrate reductases (Nar), assimilatory nitrate reductases (Nas), and periplasmic nitrate reductases (Nap). Periplasmic nitrate reductase (Nap) and formate dehydrogenase (Fdh), both belonging to the DMSO reductase family, subfamily I, have a very similar structure, but very different activities. The show key differences that tune them for completely different functions in living cells. Both enzymes share almost identical three-dimensional protein foldings and active sites, in terms of coordination number, geometry and nature of the ligands. The substrates of both enzymes (nitrate and formate) are polyatomic anions that also share similar charge and stereochemistry. In terms of the catalytic mechanism, both enzymes have a common activation mechanism (the sulfur-shift mechanism) that ensures a constant coordination number around the metal ion during the catalytic cycle. In spite of these similarities, they catalyze very different reactions: Nap abstracts an oxygen atom from nitrate releasing nitrite, whereas FdH catalyzes a hydrogen atom transfer from formate and releases carbon dioxide. Detailed comparison, overview. A key difference between the catalytic mechanisms of Nap and FdH is the fact that only Mo is used to reduce nitrate but in Fdhs both Mo and W are catalytically competent to oxidize formate to carbon dioxide	-, 742319	
1.9.6.1	evolution	the prokaryotic nitrate reductases can be subgrouped as respiratory nitrate reductases (Nar), assimilatory nitrate reductases (Nas), and periplasmic nitrate reductases (Nap). Periplasmic nitrate reductase (Nap) belongs to the DMSO reductase family, subfamily I	-, 742319	
1.9.6.1	evolution	the prokaryotic nitrate reductases can be subgrouped as respiratory nitrate reductases (Nar), assimilatory nitrate reductases (Nas), and periplasmic nitrate reductases (Nap). Periplasmic nitrate reductase (Nap) from Desulfovibrio desulfuricans and formate dehydrogenase (Fdh) from Escherichia coli K-12, both belonging to the DMSO reductase family, subfamily I, have a very similar structure, but very different activities. The show key differences that tune them for completely different functions in living cells. Both enzymes share almost identical three-dimensional protein foldings and active sites, in terms of coordination number, geometry and nature of the ligands. The substrates of both enzymes (nitrate and formate) are polyatomic anions that also share similar charge and stereochemistry. In terms of the catalytic mechanism, both enzymes have a common activation mechanism (the sulfur-shift mechanism) that ensures a constant coordination number around the metal ion during the catalytic cycle. In spite of these similarities, they catalyze very different reactions: Nap abstracts an oxygen atom from nitrate releasing nitrite, whereas FdH catalyzes a hydrogen atom transfer from formate and releases carbon dioxide. Detailed comparison, overview. A key difference between the catalytic mechanisms of Nap and FdH is the fact that only Mo is used to reduce nitrate but in Fdhs both Mo and W are catalytically competent to oxidize formate to carbon dioxide	742319	
1.9.6.1	malfunction	a gene nap deletion mutant can no longer grow on methanol in contrast to the wild-type and shows almost abolished N2O production from nitrate	-, 741478	
1.9.6.1	malfunction	Salmonella enterica serovar Typhimurium strains with defects in either nitrate reductase A (narG mutant) or the regulator inducing its transcription in the presence of high concentrations of nitrate (narL mutant) exhibit growth comparable to that of wild-type Salmonella enterica serovar Typhimurium. In contrast, a strain lacking a functional periplasmic nitrate reductase (napA mutant) exhibits a marked growth defect in the lumen of the colon. Inactivation of narP, encoding a response regulator that activates napABC transcription in response to low nitrate concentrations, significantly reduces the growth of Salmonella enterica serovar Typhimurium in the murine host gut lumen	-, 742645	
1.9.6.1	metabolism	cytochromes c encoded by genes in close proximity to the genes for XoxF proteins and methylamine dehydrogenase functions are likely involved in the metabolism with Nap, pathway overview	-, 741478	
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	additional information	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	additional information	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	additional information	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	additional information	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	additional information	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	additional information	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	additional information	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	
1.9.6.1	physiological function	napAB expression is required for anaerobic growth recovery by DELTAnarXL (a deletion encompassing the bulk of narXL)	711653	
1.9.6.1	physiological function	Salmonella enterica serovar Typhimurium uses the periplasmic nitrate reductase to support its growth on the low nitrate concentrations encountered in the gut, a strategy that may be shared with other enteric pathogens	-, 742645	
1.9.6.1	physiological function	the anaerobic reduction of NO3- to N2O is lower in Bradyrhizobium japonicum than in Bradyrhizobium diazoefficiens due to impaired periplasmic nitrate reductase (Nap) activity in B. japonicum. Impaired Nap activity in B. japonicum is due to low Nap protein levels	-, 765355	
1.9.6.1	physiological function	the Nap enzyme from Cupriavidus necator catalyzes nitrate reduction to consume the excess of reducing equivalents generated by consumption of the carbon source	-, 742319	
1.9.6.1	physiological function	the Nap enzyme from Rhodobacter sphaeroides catalyzes nitrate reduction to consume the excess of reducing equivalents generated by consumption of the carbon source	742319	
1.9.6.1	physiological function	the Nap enzyme from Shewanella gelidimarina catalyzes nitrate reduction to consume the excess of reducing equivalents generated by consumption of the carbon source	742319	
1.9.6.1	physiological function	the Nap-deficient mutant KD102 shows increased diauxic lag when switched from aerobic to anoxic respiration, suggesting Nap is responsible for shorter lags and helps in adaptation to anoxic metabolism after transition from aerobic conditions	696917	
1.9.6.1	physiological function	the single subunit nitrate reductase (Nap) appears to be involved in both the assimilatory and the dissimilatory denitrification pathways. The role in the former is supported by the methanol growth deficiency of the mutant when nitrate is used as a nitrogen source, and the role in the latter is supported by the lack of accumulation of N2O in the mutant	-, 741478