The QUTA activator and QUTR repressor proteins of Aspergillus nidulans interact to regulate transcription of the quinate utilization pathway genese.

Genetic evidence suggests that the activity of the native QUTA transcription activator protein is negated by the action of the QUTR transcription repressor protein. When Aspergillus nidulans was transformed with plasmids containing the wild-type qutA gene, transformants that constitutively expressed the quinate pathway enzymes were isolated. The constitutive phenotype of these transformants was associated with an increased copy number of the transforming qutA gene and elevated qutA mRNA levels.

Domain structure and function within the QUTA protein of Aspergillus nidulans: implications for the control of transcription.

QUTA is a positively acting regulatory protein that regulates the expression of the eight genes comprising the quinic acid utilization gene (qut) gene cluster in Aspergillus nidulans. It has been proposed that the QUTA protein is composed of two domains that are related to the N-terminal two domains-dehydroquinate (DHQ) synthase and 5-enolpyruvyl shikimate-3-phosphate (EPSP) synthase-of the pentadomain AROM protein. The AROM protein is an enzyme catalysing five consecutive steps in the shikimate pathway, two of which are common to the qut pathway.