Synthesis of bacterial flagella. I. Requirement for protein and ribonucleic acid synthesis during flagellar regeneration in Bacillus subtilis.

A relatively simple immunochemical procedure for estimating flagellar protein was developed. This procedure involved measuring the binding of purified, radioactively labeled, antiflagellar antibodies to bacteria. The assay was used to determine the requirements for ribonucleic acid (RNA) and protein synthesis during flagellar regeneration in Bacillus subtilis. Immediate inhibition of flagella development was observed when chloramphenical or puromycin was added to cells. This inhibition indicated the absence of a large pool of flagella precursors that could be assembled in the absence of protein synthesis. When the cells were starved for uracil or treated with actinomycin D to inhibit RNA synthesis, the ability of the cells to regenerate flagella decayed with a half-life of 5.5 min. When B. subtilis auxotrophs were starved for tryptophan, they continued to synthesize flagella, although this process was also inhibited by actinomycin D. On the basis of these results, we concluded that (i) the system involved in flagellar regeneration does not have unusual metabolic stability, (ii) regeneration requires both concomitant protein and RNA syntheses, and (iii) B. subtilis continues to synthesize messenger RNA during tryptophan starvation.