Five additional genes in the pulC-O operon of the gram-negative bacterium Klebsiella oxytoca UNF5023 which are required for pullulanase secretion.

DNA sequence analysis, Tnpho and Tntac-1, mutagenesis, deletion analysis, expression under bacteriophage T7 gene 10 promoter control, subcellular fractionation and complementation tests were used to study the function of DNA located in the centre of the pulC-O operon from Klebsiella oxytoca strain UNF5023. The characterized region of the operon includes five genes (pulG, pulH, pulI, pulJ and pulK) coding for apparently integral inner membrane proteins which are required for pullulanase secretion. The results presented here and previously show that the pulC-O operon contains at least 11 pullulanase secretion genes.