Table 1.

Metal-transport and metaboli-associated genes of selected Helicobacter species

Gene	H. pyloria	H. hepaticusb	H. mustelae	Proposed function
fecA1	0686	–	Present	Outer membrane receptor
fecA2	0807	–	–	Outer membrane receptor
fecA3	1400	–	–	Outer membrane receptor
frpB1	0876	1847	Present	Outer membrane receptor
frpB2	0916/0915	–	Present	Outer membrane receptor
frpB3c	1512	–	–	Outer membrane receptor
cfrA	–	0721	Present	Outer membrane receptor
hh0418	–	0418	3 copies	Outer membrane receptor
fecD	0889	?	Present	Inner membrane permease
fecE	0888	1759	Present	ATPase
ceuE1	1562	?	Present	Periplasmic binding protein
ceuE2	1561	–	–	Periplasmic binding protein
feoB	0687	0033	Present	Ferrous iron transporter
pfr	0653	1334	Present	Ferritin
dpsd	0243	0210	Present	Bacterioferritin/Dps ortholog
nixA	1077	–	Present	Inner membrane nickel transporter
nikABDE	–	0417–0414	–	Inner membrane nickel ABC transporter
cadA	0791	0586	Present	P-type ATPase
copA	1072	0682	Present	P-type ATPase
copA2	1502	1022	–	P-type ATPase
cznABC	0969–0971	0625–0623	Present	Cobalt-zinc-nickel resistance determinant
crdAB	1326–1327	–	–	Copper resistance determinant
fur	1027	0893	Present	Ferric uptake regulator
perR	–	0942	Present	Peroxide stress regulator
nikR	1338	0352	Present	Nickel-responsive regulator
crdRS	1365/1364	1656–1657	?	Two-component copper-regulatory system

^a Gene numbers from the genome sequence of H. pylori strain 26695 (Tomb et al. 1997)

^b Gene numbers from the genome sequence of H. hepaticus strain ATCC51449 (Suerbaum et al. 2003)

^c Alternative designation frpB4

^d The H. pylori Dps protein is also known as Neutrophil Activating Protein (HP-NAP)