Table 1

Bacterial strains and plasmids used

Material

Characteristics

References

Strains

Genotype

S. meliloti

GMI211

SmR Nod⁺ Fix⁺

[20]

GMI401

GMI211 asnO::Tn5 SmR NmR

This work

GMI5704

GMI211 fixJ2.3::Tn5 SmR NmR BleoR

[18]

E. coli

ER

asnA31 asnB32 thi

[15]

MM294

Pro-82 thi-1 hsdR17 supE44 endA1

[21]

DH5 α

endA1 hsdR17 (r_k^-mk⁺) supE44 thi-1 recA1 gyrA relA1Δ (lacIZYA-

[29]

argF)U169 deoR (φ 80dlacΔ (lacZ)M15)

Plasmids

pMF457

pGD926 (IncP broad host range vector) derivative carrying a fixK-

lacZ fusion with a mutation in the fixT promoter. TcR

pCHK57

pGMI41211 (Inc-P1 broad host range vector) derivative carrying a

[31]

nifA-lacZ fusion. TcR

pMF11

Same as pMF10 but with fixT in reverse orientation. GmR

pBH1

pBBR1-MCS3 derivative, carrying an HindIII fragment containing

This work

the asnO gene and the SMb20482 orf.

pBasn2

pBBR1-MCS3 derivative, expressing asnO under the control of the

This work

pLac promoter

pUC23

pUC18 digested with EcoRI, carrying the S. meliloti EcoRI

This work

fragment containing the asnO region with the Tn5 insert. Ap^R,

Km^R.

BAC37

pBeloBAC11 containing a 100 kb S. meliloti genome fragment

[26]

carrying the asn-like region of pSymB.

pRK602

PRK600::Tn5, Cm^r, Nm-Km^r

[21]

Bergès et al. BMC Microbiology 2001 1:6   doi:10.1186/1471-2180-1-6