Many bacteria contain Class I CRISPR-Cas systems and utilize multi-subunit ribonucleoprotein complexes to interfere with mobile genetic elements. The activities of these complexes are described in detail for Type I effector complexes, showing CRISPR-RNA (crRNA) mediated DNA recognition that (i) relies on the presence of a short DNA sequence termed protospacer adjacent motif (PAM) and (ii) results in the recruitment of the target DNA nuclease Cas3. Type IV CRISPR-Cas systems also belong to Class I, but their substrate requirements have not been defined and a DNA nuclease has not been identified. Here we show that the native Pseudomonas oleovorans Type IV-A CRISPR-Cas system targets DNA in PAM-dependent manner and elicits interference in the absence of DNA nuclease activity. We found that the first crRNA of P. oleovorans contains a perfect match in the host gene coding for the Type IV pilus biogenesis protein PilN. The deletion of the native Type IV-A CRISPR array resulted in upregulation of pilN operon transcription. Reporter gene targeting assays with endogenous and heterologous Type IV-A CRISPR-Cas machineries verified effective CRISPR interference in the absence of DNA nuclease activity. Our results demonstrate that nuclease-free Type IV-A CRISPR-Cas systems can function in host gene regulation. The observed activity resembles CRISPR interference (CRISPRi) methodology using dCas9 or Type I effectors without Cas3. Therefore, Type IV-A CRISPR-Cas activity represents a natural CRISPRi system that is found in many Pseudomonas and Klebsiella species and allows for their manipulation using synthetic crRNAs.