Gene 1994, 145:69–73.PubMedCrossRef 33. Olivares J, Casadesus J, Bedmar EJ: Method for testing degree of infectivity

of Rhizobium meliloti strains. Appl Environ Microbiol 1980, 39:967–970.PubMed 34. Miller J: Experiments in Molecular Genetics Cold Spring Harbor, New York: Cold Spring selleck Harbor Laboratory Press 1972. Authors’ buy Blasticidin S contributions PvD performed experiments and wrote the manuscript, JS and JO helped coordinate the study, participated in its design and in the writing of the manuscript. MJS performed experiments, coordinated and designed the study and participated in the writing of the manuscript.”
“Background C-1027, also called lidamycin, is a chromoprotein

antitumor antibiotic produced by Streptomyces globisporus C-1027 [1]. As a member of the enediyne family characterized by Combretastatin A4 in vivo two acetylenic groups conjugated to a double bond within a 9- or 10-membered ring, C-1027 is 1,000 times more potent than adriamycin, one of the most effective chemotherapeutic agents [2]. C-1027 is a complex consisting of a 1:1 non-covalently associated mixture of an apoprotein and a 9-membered enediyne chromophore. The chromophore of the enediyne family can undergo a rearrangement to form a transient benzenoid diradical species that can abstract hydrogen atoms from DNA to initiate a cascade leading to DNA breaks, ultimately leading to cell death [3, 4]. This Sclareol novel mode of action has attracted great interest in developing these compounds into therapeutic agents for cancer. A CD33 monoclonal antibody (mAB)-calicheamicin (CAL) conjugate (Mylotarg) and neocarzinostatin

(NCS) conjugated with poly (styrene-co-maleic acid) (SMANCS) were approved in the USA [5] and in Japan [6], respectively. Recently, C-1027 has entered phase II clinical trial in China [7]. Appreciation of the immense pharmacological potential of enediynes has led to a demand for the economical production of C-1027 and its analogues at an industrial scale. Control of secondary metabolite production in streptomycetes and related actinomycetes is a complex process involving multiple levels of regulation in response to environmental factors [For review, see [8, 9]]. In most cases that have been studied in detail, the final checkpoint in production of a secondary metabolite is a pathway-specific transcriptional regulatory gene situated in the biosynthetic cluster. Remarkable progress has been made in dissecting the functions of the pathway-specific regulators. For example, ActII-ORF4 regulates transcription from the actinorhodin biosynthetic genes of S. coelicolor [10, 11] and StrR controls the streptomycin biosynthetic cluster of S. griseus [12, 13].