Figure 1.

(A) Physical map of the 3,256-bp sequenced fragment containing the TM nrdJ gene with restriction sites mentioned in the text. (B) PCR amplification of an internal fragment with primers derived from peptides 1 and 4 (Table 1). (C) Single specific primer-PCR for cloning the 5′ and 3′ extremes of nrdJ. (D) Generation of an NdeI restriction site in the translation start codon. The entire gene was obtained by joining the different fragments via the SphI and HindIII sites.