Analysis of a two subunit extradiol dioxygenase derived from pseudomonas resinovorans CA10

Abstract

Carbazole (CAR) in oil is toxic, and is difficult to decompose to assess its structural stability. Nevertheless, it can be used as a nutrient source by Pseudomonas resinovorans CA 10.Extradiol dioxygenase (CarBaBb) is one of the most important enzymes in the CAR-degradation pathway, which also involves angular dioxygenase (CARDO) and hydrolase (CarC). CarBaBb is unique•among the common bacterial enzymes because it is composed of two subunits, CarBa and CarBb. However, its pattern of expression, subunit structure, and method of assembly are unknown. The gene arrangement of carBa and carBb overlap by 1 base, and so they are expressed from the same mRNA. Therefore, it is possible that CarBa and CarBb may both be translated and expressed concurrently as CarBaBb proteins. In this study, we assessed the expression conditions of CarBaBb, and examined the effects of adding spacer DNA between carBa and carBb on their expression.