Table 1.

Main components of the H. pylori NIF system.

HP numbera	ID	Uniprot entry	Name (proposed function)	Essential?b	Amino acids (size in kDa)	Interactions Fe–S prots (number of interactions)c
HP0220	NifS	25008	l-cysteine desulfurase (sulfur donor)	Yes	387 (42.4)	Yes (6)
HP0405	NifS-like	25161	NifS-like (unknown)	No	440 (48.5)	Unknown
HP0221	NifU	25009	Main scaffold protein (Fe–S synthesis)	Yes	326 (36.4)	Yes (29)
HP1492	Nfu	26025	Nfu-type (Fe–S carrier)	No	89 (10.1)	Yes (15)
HP0207	ApbC/Mrp	24999	Member of Nbp35 ATPase (unknown; Fe–S carrier?)	Yes	368 (40)	Unknowne
HP0277	FdxA	25054	Ferredoxin (unknown; Fe–S carrier?)	Yes/nod	84 (9.5)	Unknowne

^aHP number refers to strain 26695²⁶.

^bBased on chromosomal mutagenesis attempts (as found in this study, or as reported by^28,29,34).

^cAs reported by²⁹.

^dH. pylori strain specific (as found in this study, and as reported by³⁴).

^eBefore the current study.