Table 1 Bacterial strains, plasmids, and primers used in this study

Strains

Sulfobacillus acidophilus TPY

Gram-positive, acidophilic, moderately thermophilic, isolated from a hydrothermal vent in the Pacific Ocean (12.2′29″N, 104.2′01″W; water depth 3083 m)

[28]

E. coli DH5α

F⁻, ∆(lacZYA-argF)U169, recA1, endA1, hsdR17(rk⁻, mk⁺), supE44, thi-1, gyrA, relA1

Invitrogen

E. coli DH5α (pET-32a(+) -hpaB)

E. coli DH5α harboring plasmid pET-32a(+)-hpaB, Ap^r

This study

E. coli DH5α (pET-32a(+) -hpaC)

E. coli DH5α harboring plasmid pET-32a(+)-hpaC, Ap^r

This study

E. coli DH5α (pET-28a(+) –mhpB2)

E. coli DH5α harboring plasmid pET-28a(+)–mhpB2, Ap^r

This study

E. coli BL21 (DE3)

F⁻, ompT, hsdS(rBB⁻ mB⁻), gal, dcm(DE3)

Invitrogen

E. coli BL21 (DE3) (pET-28a(+)-mhpB2)

E. coli BL21 (DE3) harboring plasmid pET-28a(+)-mhpB2, Ap^r

This study

E. coli BL21 (DE3) (pET-32a(+)-hpaB)

E. coli BL21 (DE3) harboring plasmid pET-32a(+)-hpaB, Ap^r

This study

E. coli BL21 (DE3) (pET-32a(+)-hpaC)

E. coli BL21 (DE3) harboring plasmid pET-32a(+)-hpaC, Ap^r

This study

Plasmids

pET-28a(+)

Expression vector, Km^r, His-tag

Takara

pET-32a(+)

Expression vector, Ap^r, His-tag

Takara

pET-32a(+) -hpaB

Plasmid pET-32a(+) harboring hpaB gene, Ap^r, His-tag

This study

pET-32a(+) -hpaC

Plasmid pET-32a(+) harboring hpaC gene, Ap^r, His-tag

This study

pET-28a(+)-mhpB2

Plasmid pET-28a(+) harboring mhpB2 gene, Km^r, His-tag

This study

Primers

Sequence (5′-3′)

Restriction site

hpaB

F: 5′-AATGATATCATGGGGATTCGGACCGGCGAA-3′

EcoRV

R: 5′-GGAAAGCTTTTACGACCGCGCCTCCTTTGT-3′

HindIII

hpaC

F: 5′-AATGATATCATGGGGATTCGGACCGGCGAA-3′

EcoRV

R: 5′- GGAAAGCTTCTACCGTTCCAGTAACAAA-3′

HindIII

mhpB2

F: 5′-GGAATTCATGGGCGAAGCATTTAATAT-3′

EcoRI

R: 5′-GGAAAGCTTTTAATCGTCAAGAAACGCCGG-3′

HindIII