FIG. 2.

Cloned fragment carrying RNase H genes from B. subtilis 168. (a) Plus and minus signs indicate temperature-sensitive complementation of the E. coli rnh-deficient mutants MIC3037 and MIC2067 and RNase H activity in the gel assay. Restriction enzymes are as follows: B, BamHI; E, EcoRI; H, HindIII; N, NotI; Ps, PstI; Pv, PvuII; S, SmaI; Sp, SphI; V, EcoRV; X, XhoI. Antibiotic resistance genes were inserted in the site indicated by the vertical arrow. Scales are 500 bp for each clone. All fragments are oriented from left (distal to oriC) to right (distal to terC). (b) Locations of the three genes cloned in this study in the B. subtilis physical map (19). Gene names cited in reference 30 are in parentheses. Mutations are shown in brackets.