Structural and functional analysis of the gene cluster encoding carotenoidbiosynthesis in Mycobacterium aurum A+

The fragment containing the carotenoid gene cluster from Mycobacterium auru m A+, a 3,3'-dihydroxy-isoneriatene and 3-monohydroxy isoneriatene accumula tor, has been sequenced and the exposed eight genes are organised in two op erons. The function of three of these genes, a phytoene desaturase (crtl), a phytoene cyclase (crt Y) and a beta-carotene desaturase(crtU), was demons trated by complementation of M. aurum carotenoid mutants. The eight genes o f the carotenoid cluster are highly homologous to other carotenoid gene clu sters and thus this cluster is a candidate for its introduction into mycoba cteria as a non-antibiotic reporter gene(s) as well as a source of new regu lated promoters. (C) 2000 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved.