Table 3.

Bacterial strains and plasmids used in this work

Strain or plasmid	Relevant genotype or phenotype	Source or reference
Rhizobium leguminosarum
UPM791	128C53 wild type; Strr Nod+ Fix+ Hup+	[40]
UPM1155	UPM791 ( Δhup/hyp cluster) Hup-	[19]
Escherichia coli
DH5α	recA1 endA1 gyrA96 thi hsdR17 supE44 relA1 Δ(lacZYA-argF)U169 Φ80dlacZΔM15	[41]
S17.1	thi pro hsdR-hsdM+recA RP4::2-Tc::Mu-Kan::T7; (Spr Smr)	[42]
Plasmids
pAL618	pLAFR1-based cosmid containing the whole R. leguminosarum hydrogenase gene cluster	[40]
pALPF1	pAL618 with hupSL promoter replaced by fixN promoter (PfixN)	[18]
pALPF2	pALPF1 ΔhupL	[19]
pALPF4	pALPF1 ΔhupD	[19]
pALPF5	pALPF1 ΔhupF	This work
pALPF10	pALPF1 ΔhupK	This work
pALPF14	pALPF1 ΔhypC	This work
pALPF382	pALPF1 derivative carrying hupFST gene	This work
pBBR1MCS-2	Broad-host-range plasmid; Kmr mob+	[43]
pKD3	Template plasmid harbouring FLP-mediated excision sequences flanking Cmr gene	[44]
pPM71	PKD3 derivative containing Strep-tag II sequence for C-terminal end fusion	This work
pPM1350	pBBR1MCS-2 derivative containing a DNA fragment harbouring PfixN promoter from R. leguminosarum	[19]
pPM501	pPM1350 derivative containing an NdeI-XbaI fragment harbouring HupFST under the control of PfixN	This work
pPM501C	pPM501 derivative containing a deletion of the 25 3′codons of hupF	This work
pPCR2.1-TOPO	PCR cloning vector	Invitrogen