Involved in the regulation of the sulfoquinovose operon (PubMed:24463506, PubMed:30372406). Represses the expression of the yihUTS operon and of the yihV and csqR genes. Binds DNA inside the spacer between the bidirectional transcription units comprising the yihUTS operon and the yihV gene, and upstream the csqR gene itself (PubMed:30372406). Inactivated in the presence of the effectors sulfoquinovose and sulfoquinovosyl glycerol, leading to the de-repression of the target genes. Monomer in the absence of DNA. Exhibits a high level of cooperativity once it is bound to its target DNA. Negatively autoregulated. Extended N-terminus.