Clostridium kluyveri	A5N5D2: NfnA, A5N5D3: NfnB	731998	
Clostridium kluyveri DSM 555	A5N5D2: NfnA, A5N5D3: NfnB	731998	
Escherichia coli	-	734518	
Nitrobacter winogradskyi	-	288551	
Nitrobacter winogradskyi ATCC 14123	-	288551	
Pseudomonas putida	-	742779	
Pseudomonas putida DSM 3601	-	742779	
Pyrococcus furiosus	Q8U195: subunit alpha, Q8U194: subunit beta	745371, 745843	
Thermoanaerobacterium saccharolyticum	-	741703	
Thermoanaerobacterium saccharolyticum LL1025	-	741703