SYNTHESIS OF A MODIFIED GENE ENCODING HUMAN ORNITHINE TRANSCARBAMYLASE FOR EXPRESSION IN MAMMALIAN MITOCHONDRIAL AND UNIVERSAL TRANSLATION SYSTEMS - A NOVEL-APPROACH TOWARDS CORRECTION OF A GENETIC-DEFECT

The mitochondrial (mt) genome is a potential means of gene delivery to human cells for therapeutic expression. As a first step towards this, we have synthesised a gene coding for mature human ornithine transcar bamylase (OTC) by recursive PCR using 18 oligodeoxyribonucleotides, ea ch 70-80 nucleotides in length, with codons which should allow transla tion in accordance with both mammalian mt and universal codon usage, F lanking mt DNA sequences were incorporated which are designed to facil itate site-specific cloning into the mt genome. Expression of this hum an gene in Escherichia coli leads to an immunoreactive OTC product of the correct size and N-terminal amino-acid sequence, but which forms i nclusion bodies and lacks enzymatic activity.