TABLE 1.

Properties of truncated derivatives of Av NifL

Fragment	Domain(s)	FADa	Association stateb	ATP-ADP bindingc	NifA interactiond	GlnK interactione	ADP responsef	Nitrogen response		Oxygen response
								In vivog	In vitroh	In vivog	In vitroi
Wild-type NifL	PAS1, PAS2, H, GHKL	+	Tetramer	+	+	+	+	+	+	+	+
1-140	PAS1	+	Tetramer	NDj	ND	ND	ND	ND	ND	ND	ND
1-284	PAS1, PAS2	+	Tetramer	−	−	−	−	ND	−	ND	−
147-519	PAS2, H, GHKL	−	Mostly dimer	+	+	+	+	+	+	−	−
360-519	GHKL	−	Monomer	+	+	+	+	ND	−	ND	−

^aDetermined from UV-visible absorption spectra (41, 45, 64, 93).

^bDetermined by analytical gel filtration (42, 93).

^cDerived from limited proteolysis data (93).

^dComplex formation measured by coaffinity chromatography in the presence of Mg-ADP (69).

^eAbility to bind GlnK in the presence of 2-oxoglutarate and ATP, determined by pull down assays and surface plasmon resonance (60).

^fAbility to inhibit open promoter complex formation by NifA in vitro in the presence of ADP (31, 93).

^gResponse of a nifH-lacZ reporter construct in E. coli (85, 93).

^hInhibition of open promoter complex formation by NifA in vitro in the presence of ADP, 2-oxoglutarate, and GlnK (60, 63).

ⁱInhibition of open promoter complex formation by NifA in vitro under oxidizing conditions (45, 93).

^jND, not determined.