Expression of the pyrimidine biosynthetic operon (pyr) in Bacillus subtilis is regulated by pyrimidine conditions and the PyrR protein through transcription attenuation mechanisms. NusG is a transcription elongation factor that was predicted to modulate pyr operon expression by stimulating RNA polymerase pausing. I verified the role of NusG-dependent pausing in regulating pyrB expression by conducting β-galactosidase assays of pyrB-lacZ transcriptional fusions in WT, ΔnusG, and NusG pause-defective mutant strains when grown in ± uracil.