TABLE 3.

Levels of nucleotide and amino acid sequence identity for nifH genes of P. azotofixans and nifH sequences of other bacterial species

Strain or sequence	% Nucleotide or amino acid identitya
	P. azotofixans BE1	P. azotofixans RCPG7	P. azotofixans 2RC1	P. azotofixans ATCC 35681	P. azotofixans F102	P. azotofixans SD20	P. azotofixans C3L4	Azotobacter vinelandii	Klebsiella pneumoniae	Rhodobacter capsulata	Lyngbya lagerheimii	Rhizobium meliloti	P. polymyxa	P. macerans	P. durum	P. azotofixans  P3E20	P. azotofixans RBN4	Clostridium pasteurianum nifH3 alternative (anf)	Methanococcus thermolithotrophicus alternative (anf)
P. azotofixans BE1		99	97	96	96	95	93	76	76	76	72	73	72	71	67	65	66	59	57
P. azotofixans RCPG7	100		98	97	96	96	94	76	76	76	72	73	72	71	67	66	67	59	58
P. azotofixans 2RC1	99	99		98	97	95	94	76	77	76	73	73	72	72	66	65	66	59	57
P. azotofixans ATCC 35681	99	99	100		96	95	93	76	77	75	72	73	72	71	65	65	65	59	57
P. azotofixans F102	99	99	98	98		94	94	77	76	76	72	73	73	72	67	66	66	59	56
P. azotofixans SD20	99	99	98	98	98		95	76	76	76	72	73	73	72	67	66	66	60	59
P. azotofixans C3L4	99	99	98	98	98	100		76	75	75	72	72	73	71	67	66	66	59	56
Azotobacter vinelandii	85	85	86	86	86	85	85		83	79	79	78	71	73	66	64	64	59	56
Klebsiella pneumoniae	86	86	87	87	85	86	86	93		80	78	76	71	72	67	66	66	58	57
Rhodobacter capsulata	88	88	87	87	89	88	88	86	86		76	76	70	72	64	63	64	57	56
Lyngbya lagerheimii	84	84	85	85	84	84	84	87	84	83		74	70	67	63	62	62	56	55
Rhizobium meliloti	85	85	86	86	86	85	85	84	83	91	82		70	71	63	63	63	58	57
P. polymyxa	75	75	74	74	74	75	75	68	68	68	68	65		74	59	58	59	57	56
P. macerans	48	48	48	48	49	49	49	44	42	46	46	44	49		60	59	60	53	54
P. durum	74	74	73	73	75	74	74	78	76	76	74	72	59	41		98	97	72	66
P. azotofixans P3E20	73	73	72	72	74	73	73	77	75	75	73	72	58	41	99		97	71	65
P. azotofixans RBN4	73	73	72	72	74	73	73	77	75	75	73	72	58	41	97	98		73	66
Clostridium pasteurianum nifH3 alternative (anf)	72	72	72	72	72	72	72	74	76	73	72	71	57	38	86	86	86		68
Methanococcus thermolithotrophicus alternative (anf)	68	68	68	68	67	68	68	72	72	69	69	67	54	35	80	79	79	79

^aThe values on the upper right are levels of DNA identity, and the values on the lower left are levels of amino acid identity. For database accession numbers see Fig. 3.