Genetic engineering of Escherichia coli for the production of precorrin-3 in vivo and in vitro

The construction of a new recombinant strain of Escherichia coli in which t wo vitamin B-12 biosynthetic genes, cobA and cob1, from Pseudomonas denitri ficans are simultaneously overexpressed has resulted in the in vivo synthes is and accumulation of Factor III, an isobacteriochlorin not normally synth esized in E. coli. A lysate of the new strain can take the place of two lys ates normally required to provide uroporphyrinogen III methyltransferase (c obA) and precorrin-2 methyltransferase (cobI) in an anaerobic five-enzyme s ynthesis of the early Bit intermediate, precorrin-3 (the reduced form of Fa ctor III) from delta-aminolevulinic acid. (C) 1999 Elsevier Science Ltd. Al l rights reserved.