TABLE 1.

Strains and plasmids used in this work

Res and Ps refer to respiratory and photosynthetic growth, respectively; Nadi refers to cytochrome c oxidase-dependent catalysis of α-naphtol to indophenol blue. R. capsulatus MT1131 is referred to as the wild type with respect to its c-type cytochrome profile and growth properties.

Strains/Plasmids	Relevant characteristics	References
Bacteria
R. capsulatus
MT1131	Wild type ctrD121crtD121; Rifr Res+ Nadi+ Ps+
MT-G4/S4	Δ(cycA::kan); Res+ Nadi+ Ps+	(58)
MTSRP1	Δ(ccmI::kan); Res+ Nadi− Ps−	(19)
MD2	Δ(ccmE::spec); Res+ Nadi− Ps−	(44
E. coli
HB101	F− Δ(gpt-proA)62 araC14 leuB6(Am) glnV44(AS) galK2(Oc) lacY1 Δ(mcrC-mrr) rpsL20(Strr) xylA5 mtl-1 thi-1	Stratagene
Plasmids
pMAM1	pCS1302 derivative, containing a truncated R. capsulatus petC gene cloned into the NdeI/BamHI sites, with a Strep-tag II fused at its 5′-end, without a signal sequence and missing the last 39 C-terminal residues, Ampr	This work
pMAM1ΔCys	pMAM1 derivative with Cys-34 and Cys-37 mutated to Ser, Ampr	This work
pAV6	pCS1302 derivative, contains mature R. capsulatus cycP, cloned into the NdeI/BamHI sites without its native signal sequence and with a Strep-tag II fused at its 5′-end, Ampr
pAV5	pCS1302 derivative, contains mature H. thermophilus cyt c552 gene from pCS1208, cloned into the NdeI/BamHI without its signal sequence but with a Strep-tag II fused at its 5′-end, Ampr	This work
pAV5C13SC16S	pAV5 derivative with Cys-13 and Cys-16 mutated to Ser, Ampr	This work
pCS1302	pET-3a derivative with a Strep-tag II sequence fused to GFP rendering GFP replaceable by cloning any gene of interest in-frame into NdeI and BamHI sites, Ampr	(23)
pCS1208	pBSK derivative, contains full-length H. thermophilus cyt c552 gene carrying both 5′-end NdeI and 3′-end BamHI sites, cloned into the EcoRV site, Ampr	This work
pPET1-C144A/C167A/A181T	pPET1 derivative contains petABC operon (encoding R. capsulatus cyt bc1) with petC carrying the C144A, C167A, and A181T mutations, Ampr	(40)