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SECTION I: MOLECULAR GENETIC ENGINEERING AND BIOCHEMICAL TECHNOLOGY 1511. INTRODUCTIONNCS, neocarzinostatin the first member of the enediyne family of antitumor antibiotics, was discovered as a macromolecular antitumor from Streptomyces carzinostaticus strain [1]. Structurally, this NCS comprises of four important cores, the warhead, naphthoic acid, ethylene carbonate and a methyl amine dideoxysugar named 2-N-methyl-fucosamine [2]. Deoxysugar itself is not active in most cases [3], but it plays a very important role in optimal biological activities. The removal of deoxysugar moiety results in the loss of all activity of the present compound [4]. Deoxysugar moiety is to bear enediyne antitumor antibiotic and well embed in the minor groove of duplex DNA [5], therefore positioning the enediyne moiety for cleavage [6]. Recently, Sohng and coworkers have isolated the gene clusters involved in neocarzinostatin biosynthesis containing 2-N-methyl-fucosamine biosynthetic genes [7]. The four open reading frames (ORFs), ncsS32, ncsS33, ncsS52 and ncsS53, of which putative functions as dTDP-glucosynthase, dTDP-glucose-4,6-dehydratase, UDPmannose synthase and UDP-glucose-4-epimarase or dGDP-4,6-dehydratase, have been sequenced and predicted functions in the 2-N-methyl-fucosamine biosynthetic pathways.2. MATERIALS AND METHODS 2.1. Bacteria growth condition and vectors.E. coli XL1-Blue (MRF) (Stratagene, USA) was used as a host cell for the preparation of recombinant plasmids and manipulation of DNA whereas E. coli BL21(DE3) (Stratagene, USA) was used as host for the expression of 6%u00d7His-fusion protein. E. coli was grown at 37oC in Luria-Bertani (LB) broth or on the agar plate supplementing with the appropriate amount of