Table 1 Key plasmids and strains used in this study.

   Escherichia coli XL1-Blue

used for routine plasmid manipulation

Stratagene, La Jolla, CA

   Rhodococcus sp. B264-1

Source of pB264; cannot grow above 32°C

[13]

   Rhodococcus sp. B264-1 R1

spontaneous RifR-derivative of B264-1

this study

   Rhodococcus sp. I24

orange colonies; grows well at 37°C

[13]

   Rhodococcus sp. I24 R6

RifR-derivative of I24

this study

   R. erythropolis SQ1

buff-colored colonies; RifR, StrR; derivative of ATCC4277

[8]

Plasmids

   pAL220

pB264, ligated into pCR-Script

this study

   pAL224

KanR marker from pUC4K ligated as an Eco RI fragment into the Eco RI site of pAL220

this study

   pAL231

TsrR marker from pGM160 ligated as an Eco RI-Sma I fragment into the Eco RI and Eco RV sites of pAL220

this study

   pAL281

GntR plasmid carrying NG2 origin for replication in Rhodococcus and E. coli

this study

   pAL298

GntR marker from pGM160 ligated as an Eag I fragment into the Not I site (partial digest) of pAL220

this study

   pAL305

Pst I deletion derivative of pAL298 lacking majority of pB264 element

this study

   pAL312

ORF7 from pB264 positioned downstream of constitutive trc promoter in a plasmid bearing the NG2 origin and a spectinomycin resistance marker

this study

   pAL314

ORF7 and ORF8 from pB264 positioned downstream of constitutive trc promoter in a plasmid bearing the NG2 origin and a spectinomycin resistance marker

this study

   pB264

4970 bp cryptic plasmid from Rhodococcus sp. B264-1

this study

   pCR-Script

AmpR plasmid for cloning blunt-end DNAs

Stratagene, La Jolla, CA

   pGM160

source of GntR and TsrR markers

[35]

   pJANET

majority of pB264 in vector carrying NG2 origin of replication and GntR

this study

   pUC4K

source of KanR

Amersham Pharmacia, Piscataway, NJ

   pXS9a

KanR marker from pUC4K ligated as an Eco RI fragment into the Eco RI site of pAL231

this study